I have seen this ”war” between different engine modder before and what it all boils down to is some simple facts. Every engine is a compromise, you can´t build an engine that will win dragrace and still make 10+ minutes and last 10ga and the opposite is also true.
All of those that mod engines have to make compromises and everyone make their compromises at different places and if it works they (well, at least many of them) assume that everyone else is doing it wrong. That is about as much true as that Novarossi wouldn´t know hove to make the same engine mods that many on the aftermarket does, all that can be done is shift compromises to different places and thereby come up with a slightly different engine then when it left the factory.
The only thing that can be done to improve an engine from a good company like Novarossi without altering the compromises they have made is to make subtle flow mods and make a “blueprinting” to what/where you are going to run your engine, this cost too much to be worth doing in full production at the plant and is practically impossible considering all the different places/cars/fuels etc these engines end up seeing.

In the end I think there is enough room/market for all good people that supports their customers and I wish you all good luck!