Very good if you use it the right way:
- Always cap your framerate to EXACTLY HALF of what you're seeking (if you're using X2 frame generation, which to me is the best option as it's the most stable). LSFG 2.3 seems to love and work amazing with framerate caps of 30, 60, 120 and such. You can do this with RivaTuner Statistics Server, usually included with MSI Afterburner, though you can install it standalone.
- Always run your game at Borderless and NOT FULLSCREEN! Lossless Scaling doesn't work well with Fullscreen.
- If you also want upscaling, set your game resolution to the resolution you want to upscale from, then turn on upscaling in LS. I recommend FSR with the sharpness setting at the middle.

With this formula, you should have a great time! I'm playing GTA V on high settings @ 1080p 60fps this way on my laptop with integrated graphics. Though I don't use upscaling because it doesn't work that well with GTA. Have fun!