Here are 3 pictures of the naan cook from last night.  Each recipe had 1 Tawa and 1 under grill.  The Tawa cook provided more bubbles, resulted in a more raw doughy flavour but they were softer. The oven grill cook was slower and provided a more overall rising affect as you'd expect. but resulted in a more cooked bread flavour.

Even though the Tawa cooked nice looking naan the flavour and texture is not there.  None of these tasted anything like a T/A  bought, tandoor cooked naan.  I'm undecided whether it is the dough recipe or the lack of oven heat and flavour from the Tandoor oven.  In comparison I would only give the best of these a 6/10. They just don't do it. As for the recipe in this thread, it is bland and lacks flavour.  Someone said in this thread that H4ppy Chris does not add salt as Self-raising flour already has salt in it.  Not here.  It has sodium from additive 339, 450 and 500 but does not contain NaCl..

I've read that some people are very sensitive to the metallic taste of Baking Powder and I must be one such individual.  I can't yet say for sure which of the 2 non-yeast naan was responsible, if not both, but I had the clear metallic after-taste of Baking Powder overdose for over an hour after eating a small end off every one of these naan,  I will today taste test the yeasted ones first followed by the BP varieties with a time gap in between to see which creates this taste.  I do not experience this with purchased naan cooked fresh.  A possible cause of the problem is that my Baking Powder is out of date. I'm not sure how critical the Best Before date is on a container of Baking Powder.

Edit:
After taste testing again this morning there is no doubt that it is the additional Baking Powder combined with what is already in the SR flour that is causing the after-taste in H4ppy Chris' recipe.  The naan are fully cooked through so under-cooking isn't an issue. I don't get the after-taste from the generic Restaurant Style recipe which used Plain flour instead of Self Raising and used the exact same amount of added Baking Powder from the same container.  It rose and bubbled adequately without Self Raising flour. Not as much bubbling but enough. Again I found the absence of any salt in H4ppy Chris' recipe to provide a bland product.  There could be a regional difference in ingredients; ie SR Flour having added salt or not.

I'll answer more tomorrow Sverige but 30 g per kg is actually probably a bit light. 4 - 5 % is common so that's 40 - 50 g per kg. I just don't like added baking powder. Scones, pikelets, pancakes or naan. I can taste it afterwards. Bitter metallic and it lingers in my mouth. Apparently when adding baking powder to plain flour to make your own self raising, it should be sift mixed completely at least 3 times. I don't taste it when just using store bought SR flour.
I did find 1 UK source that added salt to home made SR flour but you are correct in the US being standard salt included.

Additional answers.
H4C recipe will taste better with the addition of salt and removal of baking powder so all is not lost. The other 2 recipes used were a generic "Restaurant Style" naan from the Celtnet.org archived website and a Tandoori Roti recipe from and old Indian cookbook. The first is not dissimilar to H4C except it uses plain flour and baking powder and the Roti ingredients and method are the same as any other naan recipe.

The main thing is that I can make successful bread using many recipes but I'm yet to find one that tastes like a bought tandoori naan. They just don't. 

As for technique, if you sit and watch videos on naan as I have you will see that some say minimal kneading otherwise you'll have too much gluten while others say full gluten development is required. I've tried both and everything in between.

Ingredients, I've tried many different combinations from the basic 5, flour, water, sugar, salt and either yeast or baking powder, and sometimes both. I've then included milk, egg and yogurt in various combinations or singly. I've used different hydration percentage and even bought actual Indian Maida and atta flour. I've used Self raising, plain and even strong bread flour. All of these make a thing that look like a bread product and now with the tawa technique, like a naan. But they don't taste like one and they don't have the soft flexible texture. They taste like a bread but not like a naan.

Yesterday I made a single naan quantity of the buttermilk recipe from The Artisan baking school video. I'll cook it on the tawa today. I can't imagine Indian takeaways and restaurants go to any great lengths to hide a secret with naan so I feel it is down to the tandoor oven. I'm not sure but I can't get the same result at home and I know my way around the kitchen.

A bought naan is cooked through but so soft it can be folded into a foil bag. If it isn't eaten, the next day it can be reheated and is just as soft and still tastes like a freshly cooked naan. This simply does not happen at home.

Less kneading gives a grainy, crumbly mouth feel which is not how a naan should be. More like cake. As naan is bread it requires gluten development.

Nice-looking naans, Mr Zimmerman, but confused by your comment "No salt, Sr flour contains raising agents".  Are you saying that the presence of salt would render those agents less active ?

** Phil.

Is it rolling Bob? Sorry to say I don't agree with you.
The cooking technique is now well known and several tawa naan videos are out in the public domain. As for ingredients? Not the best recipe in the world obviously as you've already changed it by halving the sugar content. I would add these points as well. The baking powder is excessive, if really required at all. No salt is bland and tasteless (except for BP after-taste).
I've used 2 different recipes recently that produce far better results. My own extensive testing of this recipe has shown that the extended "necessary" wait times are not as critical as claimed, and in fact the use of chemical raising all but negates this requirement. Some fermentation may occur for flavour over this time but under refrigeration, it will be minimal. The bench rest is important to relax gluten but the hours mentioned as "required" are excessive. Excellent quality naan can be prepared and eaten within hours, not days. If you want more flavour profile use a starter, but still easily possible for same day prep and cook.
Edit, salt only present in SR flour purchased in the USA. Not anywhere else.