Im not sure who would hate this proposal. Watching free throw fests is excruciating. The Spurs/Thunder was an absolute chore to watch.
When attempting 2 free throws, I've seen stats where the %age on the first and second FT's were both in the 70's, but the 2nd FT %age was a bit better. I remember reading a Reddit post on the stats when shooting 3 FT's, but I can't remember the exact numbers, but the %age increased from 1st to 2nd to 3rd attempt. The 3rd attempt was up close to 90% from what I recall.
From looking at it, It... will. TS% is basically points per fga's and fta's (simply-put). Now you'll be scoring more pts per fta's. I'm basing this on the assumption that these shots will still be awarded 1 FTA like, I believe, the G-League has been doing it for the past few years with their one-FT rule. Not to mention if/how the actual calculation of TS% itself will need to change. Let's just not change it! lol. It's only fair.