I completely agree. They really need to increase that to 4 foreigners on court allowed at the same time. That created an advantage to Italian teams and as we see, it didnt influence the development of their NT either, actually had a reverse effect where they do better recently.
Mathematically it also makes sense. Yes, Turkish NT is one of the top 5 in the world and have 12-14 valuable players but if you distribute 4 players in each team (3 are needed on court), only 3-4 teams can have solid local players, rest have to fill in their squads with whoever they find. In a league of 14 teams, if you want better competition, you should definitely change the foreign player limit. Other option is to reduce number of teams to 12 or 10.