I am sure you base your comments of direct experience in setting up your own vehicles in terms of hardware and tuning? as do I.
If not, then with all respect , you can not accurately comment on a subject you clearly know little about.
I'm not going to get into a debate, the OP asked advice, I gave some based of my 'actual' experience over a good few years of working on these vehicles, not paying someone to do it for me.
The Subaru boost control is a great tool from the factory, the ECU is very powerful, this is ample for 95% of end users, however it can be improved on for specific set ups/ power goals., this includes MBCs
Sure the OP does not need to change his controller but he has, its his choice and his car can run well with it, If set up correctly.
Unfortunately, the forums have a lot of mis information based of hear say.