Tsss... can't insert my reply in the middle of this, so it will do here :
1 : Not for me, sorry, I don't know exactly what happens for you, but the rom loads fine here.
2 : Ah ok for this one, the -romcheck command doesn't handle very well the roms loaded with a ROM_CONTINUE, actually these roms are very few, and it's the 1st time this is reported... Anyway what happens is that it says bad size 0x20000 because the rom is loaded by parts of 0x10000 with a ROM_CONTINUE for the 2nd one. It's harmless anyway, but thanks for the info.
3 :Since you didn't give any example I am obliged to guess here, and chances are you stumbled on another game using ROM_CONTINUE, like sonicwi3 for example... !
That means also that nobody seriously used -rcf in the many years it existed, it's from before 2009 (start of git in august 2009, and it was already here).
Wow, it just shows I spent too much time on this already !
I'd say not worth fixing it for now, sorry !