When you type S you should get the following menu:
'
S' > type first letter or more to continue filtering > 'enter' (no need to tab down to 'ok'.)
'T' to tag something.
So yes it's 3 keystrokes now, but if you have 10+ tags/searches it's a much better system. Plus you don't have to remember key mappings. (Same method is used for moves 'm' - folder views 'v' - and tag views 'vv'.)
For a bit I renamed my tags/searches like '1Name' because I kept doing the old method subconsciously. (Unlike searches, tags have a minor quirk that after rename you need to reload the browser or it won't find the name yet - guess I'll bugzilla it.)