There will always be a market for growth comics of any form. Keep in mind various things you choose to do will always shrink or expand the niche you find willing to pay for them. So good suggestion is to always make sure you can have fun with it before considering the 'will it make money' approach. Doubt you'll have anyone opposed to it in other words, besides those who want it but would miss out due to their own money issues, and as long as you want to do it I'd say you should ignore them should do it anyway, lol.

Admit Male sonic character to female-Fat/Curvy is a bit outside my own niche though.