Back in the 80's with GI A1 pattern pistols incl the left side only safety I shot with my thumb locked down but since returning to working with 1911s more recently I adopted the thumb on the safety and found I liked it much more. And this is more modern format pistols re ambi-safeties etc.
It complimented (or so I think) my dual use of Glocks with high thumbs. It did not play well with the USP I briefly owned though, I'd re-safe during strings of fire.