Why is Microblock Chiseling disabled in more "hardcore" presets?

[Mummel]

Am i correct in thinking that this is just down to microblocks not interacting with "cave-in" physics? Can chisels be used to cheese mineshafts? Totally new player here, if that's the only issue I'm perfectly fine with just not "abusing" chisels, these two features apparently clashing is just a bit of a bummer.

[Varcii]

I play with cave-ins and as far as I know you technically could leave extremely tiny bits of a block left to not trigger cave-ins, though it would be much more tedious and ineffective compared to just, using support beams