So let's summarize: I can use BrainsOS+ on solo pool and there was a proof that this software can find block. Am I correct?
No idea if it can find a block, but proof it can hash >32bit shares - which is one well known historical example of losing blocks ... that happened on slush
I heard about Vnish which is using open source software under the hood but I can be wrong.
Vnish is a full on lying bunch of scumbags who also violate my cgminer license.
Do you have any suggestions how to solo mine "the right way"?
Mine here solo for the ridiculous low 0.5% fee
If you want to do it yourself, then be prepared to spend $15k a year on fast bitcoin nodes to distribute you blocks around the world.
Of course it will still be slower than here.