I don't think that such a computer is relevant for performance testing. I tried it on several moderately old computers and the performance was good.
that is like avoiding the issue. if VS and other editors are not lagging on that feature at all than it means something is wrong with the current implementation.
see for the compare with B4J which I mentioned earlier that is a lot faster.
when I keep pressing a letter in B4A nothing appears till I release the button and wait a few more seconds till it went through all lookups or source checks.
I still have to find another editor that has this kind of behaviour.
My guess is that the problem is the log update (see attachment) that seems to go over the entire source on every keypress, maybe that should only be done at line change or compile?