Character portraits - expanding and general other things to do with them

I'm currently looking into expanding character portraits to match up with the new NPCs in battle/party. That'll get done in some form or fashion (be it a full table or just a default thats not glitched for any NPC). No questions there as of today.

It did make me think of this however;
Character portraits in dialog

That thread ended with no result, just things that didn't work if I read it correctly. I almost remember another saying it flat out wouldn't work.

Why bring it up?
C3/6711 20 41 03 JSR $0341 (Draw window that holds character portrait)

Why couldn't that just replace your normal dialog box? This isn't part of my current project I'm just wondering if anybody ever tried it? Yeah, it would load a portrait for every window... I think, or a blank space similar to the party menu while no character in slot. But would it work at all? I'm talking about replacing the window for text, not doing it from the dialog, and putting a little code to load a character or null and have it all execute from the normal dialog command, not the text within.

Would it have any hope or does something like VRAM kill it?