When looking at the data-segments I saw, that you mostly used $6000-7FFF or just 8k of the available 16k rambanks ($4000-7FFF), WHY ?!?
When Kyle asked about supporting the RAMBO 1088K I said it sounded like a possibility but that I'd leave it until the end as I didn't really want to support another variant during development. However after finding out how RAMBO 1088K worked (thanks to the excellent Altirra h/w reference manual) by only using half the banks at $6000 I get the same layout as the 5200 version. So the 1088K version only exists now because I could do it for free (well it was a couple of hours work - selecting the 5200 bank layout with 8-bit code options, different macros for bank selection and turning the resulting cart image into a xex).
I don't really know where we'll end up as it's not like any of this is planned in advance. If we end up using the entire 1MB of the MaxFlash then perhaps we will make two 5200 versions - they will be 512K so are possible candidates for what you suggest.