Two weeks ago I got myself an Ilyama 24" monitor, that was "g-sync compatible" - yep, bit of a risk, but it worked out fine. Nvidia control panel shows it can enable G-Sync, and in game I see 144hz ... so, it works. Euro 217,= was its price. (Connected to 1080ti)
Beats the 437 I paid three years ago for same size/specs Acer 24", with true G-Sync support...
(Just saying, besides G-Sync and FreeSync, G-Sync compatible exists, and can work)