"Change block type" makes more sense then "Change block language". "Language" sounds like it could mean English, French, etc. whereas "block type" is unambiguous.

All blocks should be collapsable - I was playing with it and had to enter a comment marker in some to be able to get the collapse arrow in the bar, like # in a python block, however the behavior for a python block collapsing vs another - is that the python block collapses to ' ... ' Whereas, other blocks maintain the firt row as a header, so if I label another block NOTES and collapse it, I can still see the header.

So a collapse button on every block would be nice.

I love this. Thank you.

It would be nice with some documentation of what the Math mode supports, e.g. syntax, units, functions.

It can be difficult to figure out why some lines are interpreted ok and while others fail.

How to convert between fahrenheit and celsius?