is difficult to understant why MikroTik do things like this
CSS106 hav a basic RSTP support with no tunable timers or values, that makes this function very useless
But the worst part is, when you disable RSTP switch does not allow BPDU pass so if you plug it on a STP/RSTP topology you can make a loop easily
Even cheaper non manageable switches pass BPDU transparently avoiding this kind of problem