Actually, I felt myself getting a bit annoyed at this whole line of questioning... but I bit my tongue, and after a while, it dawned on me that maybe a bit of perspective would be a good thing, so here goes:
When I started work on Free42, the app upon which Plus42 is based, it was 2004, and the first platform I had in mind for running it on was the Palm m100, a low-end PDA that was popular at the time. The m100 had a 16 MHz 68000 CPU and no hardware floating-point unit, and it had a 160x160 pixel 2 bpp (4 levels) grayscale screen.
For comparison, that's about the same number of pixels as one icon on a recent iPhone's home screen, and the CPU is about 100,000 times slower than current smartphones.
What this means is: back in 2004, it was all I could do just to get Free42 to run at roughly the same speed as a real HP-42S, and the keyboard and display barely fit. Retina screens and fancy fonts weren't on anybody's radar.
Of course, hardware development hasn't stood still in the nearly 18 years since then, but I had my reasons for not supporting every little UI innovation.
The big one was OS churn. I initially developed Free42 for PalmOS and Linux (the latter using the Motif widget set). Once they were done, I ported it to Windows before releasing 1.0. And in the years that followed, I added more and more functionality to the UI, like program import and export, and the print-out window, meaning every subsequent port was going to be more and more work. And there were ports: to Windows Mobile, to PalmOS on ARM, to Linux using GTK widgets, to Android, to iOS, and to MacOS, and I also added even more functionality to the UI, like customizable skins, portable state files and quick state file switching, audible and haptic feedback, landscape mode, Unicode support, 64-bit support, copy & paste for all data types including programs and matrices... And lots of core functionality as well, like the big stack, local variables, long strings, et cetera.
And I did all this while also living a life and working a full-time job.
I'm not complaining, I wouldn't have done it if it wasn't fun, but maybe this helps get the point across how it might be possible that features that may make perfect sense have nonetheless, somehow, not gotten done yet.
If Plus42 sells well, maybe I can make it my full time job and then I can implement everything anyone has ever suggested, but if not, the pace of progress will remain slow and unpredictable. I'll need to sell a lot more units to make that happen, though, so, spread the word!