Privalov,

Could You add the directive which inform compiler to use only this version of possible op-codes to become output's code relocatible?

I have never met before this kind of directives in other assemblers, so You will be The First!

Please explain what do you mean with more details.

to write flexible code independent on system and memory allocation,
you can do many kind of trick with it,

exploitation will become much easier hehe
I have no Idea but it is intresting, What do You think?