the original recipe clearly says it cannot be reduced in volume (which I find a bit weird anyway).
I have experimented with large quantity bases versus a scaled down version.
There were two main differences I noted, but not where I expected to find them
Firstly the chilli heat reduced drastically
Despite using a very hot spice mix, the base had little heat
Secondly, the sweetness increased
I found this was directly proportionate to the salt (yes, salt) used
More salt = more sweet
Perhaps the results I got were also related to the length of time needed to cook the base
The base was cooked for three and a half hours, then left to stand overnight before pureeing