You don't find the TX-6 too small? That's what's preventing me from even considering buying it. If it were a little bigger, I'd be dreaming about getting it, or perhaps even actually getting it.
I got to fiddle around with one. I have probably average sized male fingers, and it really wasn't a problem at all. Tbh if there's one thing you can pretty reliably count on TE for it's spectacular minimalist design, but if there's a _second_ thing it's thoughtful ergonomics.
Look at the 1010music Bluebox. It's about twice the size of the TX-6, half the price, and infinitely more usable as an actual mixer and multitrack recorder.
i know it, it's a decent alternative. it's not useful as a bluetooth controller (I use TX-6 for both mixing inputs as well as software mixing sources on the iPhone), it's not an audio interface. the bluebox also has no battery so you have to increase the size further to attach one. does not fit the same use cases. not what you'd get bluebox for but I also use TX-6 as a BTLE performance device apart from its mixer capability (like the TX-7 stem player prototype was before it had any audio inputs) which again has nothing comparable that can be handheld.