There's no concern about features not being supported. But I still think you should give the 12.9 another look.… UNLESS you're really never going to work on larger or more complicated models. In conclusion if you want the Pro 11, buy more Airs instead, in my opinion. It's completely worth the extra investment and I wouldn't swap it for more frequently upgraded iPads Air. With that said, the Pro 12.9 is a much nicer device with a better screen. By the second upgrade you do, you'll have a more powerful CPU than if you had kept an iPad Pro for longer.… and to me the size difference between an iPad Air and a Pro 11 isn't big enough to be worth the extra cost. If I didn't want the 12.9, I would settle into a routine of buying into the iPad Air tier, and maybe upgrading more often and having a newer fresher device every couple of years. Also with iPad OS having mouse and keyboard support, you can transition between using it as a laptop, and using it with the pencil pretty easily. I think you get used to a bigger iPad a lot easier than trying to model in a confined space.

I understand if you think it's too big, but the extra real estate really helps when you're working on more complex models. As a Shapr user, I really can't suggest anything other than the 12.9' iPad Pro.

Shapr3d macbook pro