I would very much like to recommend this software as 1, it is very cheap, 2, it works very well for what it does, 3 has an active developer.

However, the use of the software prevents VRR such as GSYNC from working, and this is not explicitly stated on the product page. In the software itself, it seems to be "up in the air" whether VRR was, is, or will be supported. In the developer's discord there was mention that (paraphrasing) "the functions to call the GSYNC/VRR are unknown/not documented, so there is no ETA on adding this".

In case the developer is still stuck on this, I highly recommend reaching how to the developer of SpecialK who probably has the foremost knowledge of these things above anyone who doesn't work at Nvidia, and probably most of them too.

If you do not have a VRR monitor then by all means purchase and use this software according to its specific directions and you will be impressed.

The second VRR support is added I will rebuy this software and change my review to recommended. Best wishes!

✔️

-i updated the drivers to 555.99 in geforce experience (i saw a lot of ppl complaining about previous nvidia drivers using a absurd amount of GPU when using scaling programs)
-second i opened the nvidia control panel and added a custom .exe in the graphics settings (i added this app exe) and change LATENCY setting to ULTRA, and VSYNC to OFF.

all that said, there's my config for Lossless scaling:
SCALE MODE: Automatic, Fullscreen
SCALE TYPE: LS1, Sharpness to 0, Performance ON
FRAME GEN: LSFG 2.0, Performance ON, Exclusive cursor ON, Scale Cursor ON, Show FPS ON.

that's it, i restarted after all that and all stuttering and weird behavior is gone, i hope it helps you.