Wel, I've never been in a BIR kitchen, but some who have say that commercial paste is standard in small quantities- if that's the case then in order to emulate the BIRs, we would have to use the paste too.
HOWEVER- of course it might depend on which era of BIR cooking we want to aspire to- and if it's from before commercial pastes were being used, then it would indeed be wrong to use it.
Not that there's any
real right or wrong in this game, surely?!?!