As UK is out of the EU some reciprocating agreements are no longer in place.
I am a UK citizen and before Brexit Eire had a visa waiver scheme for Thailand nationals that had a UK visit visa. Which was great as France declined a visit visa so we spent a week traveling around Eire and very nice to it was.
you will have a 6 month grace period out of the kingdom so will not look too suspicious. It's when is back to back year in and year it raises a flag if an immigration officer is not feeling the love on that day.
Bear in mind the 60+30 can change at any time. It was a post COVID sweetener to get people into the Kingdom. It's now helping Russian men not having to go back to Russia. It's drives more tourist $ into the economy so always a balance. Retirement visa if you can meet the criteria is the way to go. You can get a bank account and other bits sorted.