Zoe:
I wore a hijab outside of the towns because people are not that "modern" there and I got bad looks if not
Out of interest to understand how things might have changed.since we were there.
I presume you wore a black abaya all the time whether or not you also wore a hijab?
My wife and I were there in 2002 during an earlier "attempt" by Saudi at encouraging tourism and issuing tourist visas. That was after 9/11 but subsequent World events, struggles among contending views for influence in SA etc put an end to that initiative.
We had to travel as a "group" and the females wore the abaya (black??) all the time - actually this was no "problem" as it avoided the need to consider what to wear! In fact, although my wife had bought one she was also "issued" with one by our tour company on arrival!! The hijab (also black) was still required at all times - even for my wife's visa photo (as more recently, though of any colour, it was for her Iranian visa photo) - what was your experience in that respect? In Iran in 2016 her adoption of head covering was somewhat perfunctory - she wore a coloured head scarf but plonked her usual crumpled bush hat on top of it -with no criticism or obvious "comment"!
We didn't actually face them personally, but the "Mutawa" or "religious police" were noticeable in Saudi. Particularly at prayer times they would drive round and "encourage" shops to close (many shops were of course at least staffed, if not owned, by South Asian and other immigrants.) Did you see any sign of the Mutawa?