Nice freememory function!
I love the idea of adding this as a compile step, I’m guessing I’d just run something like…
arm-none-eabi-size user-firmware.elf
and include some kind of output like:
text data bss dec hex filename
65292 2912 11532 79736 13778 user-firmware.elf
Yeah? I could add that as a compiler step, but it might take a while before the web ide is updated to show it – gotta check with those guys. Adding it to my list! 
(We are really keeping track of all this stuff)
Thanks,
David