With Mbed Studio 1.2.1 I was able comment out a section with CTRL + K + C, and uncomment with CTRL +K + U.
This is not working for me in 1.3.0 anymore. If i use CTRL + Shift + P to find the command and klick “Add Line Comment” there, it works as expected.
You should still be able to use: ctrl+ / - toggle line comment, supports commenting multiple lines when more than one line is selected shift + alt + a - toggle block comment, supports commenting multiple lines when more than one line is selected
As Matthew mentioned next release of Studio should allow to view and modify all shortcuts. Here is a sneak peek into this feature: