I kind of recall that in Turbo Pascal or early Delphi versions there were options to make functions calling convention not register by default but any other type.
Maybe i mistake it for {$W+} or {$STACKFRAMES ON} option, which affects functions prologue and epilogue as well.
I do not want to use pascal pre-processors, but if i could change default convention for some unit it could be useful to me.
It cannot be done. The default calling convention cannot be modified by compiler options.