I understand that the conversion will be automatic actually otherwise that would be really quite laborious.
Yes I agree about one single hashtag being easier but I don’t think you’re right about needing 4 keystrokes. Currently and on the new version you only have to do one half of the brackets and the system inserts the other half. So typing ‘[’ will result in the computer entering the other side ‘]’. It also doubles up so typing ‘[[’ leaves you with ‘[]’ but the cursor is still in the middle rather than at the end so you can then just start typing the tage/page reference you want.
Admittedly typing # is quicker but just double tapping [[ isn’t that much work. Also after you’ve found your tag and selected it the cursor then jumps to the end so you can carry on typing.
I think this functionality has basically always been there. It also works for other brackets as well as some symbols which add formatting like * for italics and bold.