I have a Next engine and compiler but at present it doesn't support Next sprites, only Timex 8x1 attributes. The intention is to add this at some point but I don't get a lot of people asking for me to do this so other things have priority for now.
Viewing post in Multi-Platform Arcade Game Designer comments
I’m surprised the chatter hasn’t gone into overdrive for a Next version which would make use of the extra features and memory.
Being able to develop on the PC using MPAGD and then output a .nex file would be a thing of beauty and something I would pay for.
I think this is where the Next is lacking in having a full out of the box dev environment.