I'm not sure about that. The opponents usually aren't converting 100% themselves. Two end of the floor stuff
for instance, last night the Blazers shot 67% on FT's. If they shoot their season average they score 4.7 more points in an 8 point game. So, 5 more points. But...Detroit shot 62%. If they shoot their season average they score 3 more points. Blazers only net 2 more points if both teams shoot their average. Not only that, the Blazers shot 14 more FT's than their average while Detroit shot 5 less FT's than their average. And this was in a game when Detroit had a 66-40 advantage in points-in-the-paint. I think context matters
* in Portland's case, more context: Blazers are only 20th in FT%. But they are 3rd in FT's and FTA's; they get to the line at a high rate. Trouble is Blazers are 27th in fouls; 28th in opponent FTA's; and 29th in opponent made FT's. The result of all that is they only outscore opponents by 0.3 points/game from the FT line
* more context, part two: say the Blazers ranked 10th in the NBA in FT%; that would be a conversion rate of 79.2%. Portland's current rate is 78.3%. The Blazers would only score 0.26 more points/game
* more context, part three: so then, if Portland had better FT shooters, would those better FT shooters be able to get to the line at the same rate the current ones do? That's seems pretty iffy. CJ and Simons are good FT shooters but they are terrible at getting to the line. Deandre Ayton shot 82.3% from the line his first season in Portland; but he only shot 1.6 FT's/36. Clingan is averaging 3.6
if the Blazers want the FT line to make a bigger difference they might want to foul less