I don't believe it is necessary. I proposed a mapping that would be compatible with the original cart, as well as already work with existing emulators back in 2012. But, byuu shot it down and insisted on doing things the BSNES locked-in way instead on grounds of needing more space for some super secret translation feature that never took place.
As it stands now, no flash carts, or emulators will play this. Only BSNES/higan (and probably only certain versions that are compatible with that particular version of the manifest file). 
Hi Nightcrawler... I understand your concern but Tom gives the shots here, not Byuu.
Byuu and LostTemplar did the right thing about the expansion. There is no secret here. The game only has 1MB of "cpu rom" so it was expanded to 2MB, and in the right way.
We can expand the SPC7110 data block too, and there is only one way to do that. And the expansion was needed because the new script size.
And there is no such thing like "BSNES locked-in way". Bsnes is the emulator that gives you the most freedom among all Snes emulators. The philosophy is just contrary to "lock-in" implementation. This manifest feature is amazing because gives you complete control over the Snes memory map. You can do whatever you want.
People complains about the folder method used by Bsnes/Higan, but this is another amazing feature after you look at it. It's even better for debugging. I use the v086 debugger and this folder stuff is just amazing. All debugging files are completely organized and keep saved among debugging sessions. Far ahead other debuggers.
And it's all open source, with very good code. So you can add any features you want easilly just implementing directly in the code. I did a lot of modifications and added some new features in the debugger while working in Feoez.
Bsnes/Higan doesn't have a lot of features like other emulators, like video recorder, video filters, etc, but for debugging, testing, etc, it's the best choice (to me).
I'm not advocating in Byuu's favor, but I think I got used to how Bsnes works. Today I think it's impossible to me to work with Geiger again. But it's only me, other people may think Bsnes is shitty. No problem with that.
As it stands now, no flash carts, or emulators will play this. Only BSNES/higan (and probably only certain versions that are compatible with that particular version of the manifest file).
Yes, but the problem here is the SPC7110. The expansion is very simple, like the expansion of any other game, but because we have the SPC7110 the emulators will need some patch. Snes9x for example checks for the SPC7110 and uses a custom map if it's found, so we don't have control to make it to work, so we need to release a new version.
If you have another method to map new space please let us know. But I think the game is already expanded in the right way, but who knows? But only using the original size is out of question, because the translation really needs extra space.
I think the most important thing for a translation is to be 100% compatible with the real hardware, and currently the game is. If it needs to change a lot of software to be able to play this translation, so be it, because it's a price to pay to play the game in english.
Like I said if you have suggestions please let us know. I think we are all willing to receive suggestions and implement it if it's worth of it. I think Tom's intention is to release the best translation possible. Like I said Tom gives the shots here (not Byuu) and he is very open to suggestions.