^^^ Guys, I don't want to spoil the fun but..............
I wouldn't use a "2nd brain" to control something like ALS besides the ECU.
I have seen a lot of cars go POP because they have too many electronic gadgets that control too many different things without proper failsafe links between them.
In my opinion if the ECU you are using cannot do everything you want to do then it's time to look for one that can!
BTW... The "Subaru Rocket" setup is indeed a selfsustaining turbine when it is spun up. It would be nice to try to replicate this kind of ALS but unless you are sponsored by a turbo manufacturer who gives you turbos for free I would try to stay with more conventional methods of ALS.
The biggest advantage of the "Rocket" versus conventional ALS is that the air to keep the turbine spinning DOES NOT have to pass through the engine. Therefore the engine stays much cooler and has to handle less stress. Conventional ALS has the air passing through the engine with ignition retard creating very high EGTs to spin the turbine which is passing the exhaust valves which are not going to be too happy about that.