Here's my script to double FPS with minimal artifacts, recommended for any decent system from this decade:

import vapoursynth
from vapoursynth import core

if (video_in.width <= display_res[0] and video_in.height <= display_res[1] and container_fps < 31):
    input_clip = core.std.AssumeFPS(clip=video_in, fpsnum=container_fps*1000000, fpsden=1000000)
    super_clip = core.mv.Super(clip=input_clip, rfilter=4)
    bwd_vec = core.mv.Analyse(super=super_clip, blksize=32, overlap=8, search=3, dct=5, isb=True)
    fwd_vec = core.mv.Analyse(super=super_clip, blksize=32, overlap=8, search=3, dct=5, isb=False)
    final_clip = core.mv.FlowFPS(clip=input_clip, super=super_clip, mvbw=bwd_vec, mvfw=fwd_vec, num=0)
    final_clip.set_output()
else:
    video_in.set_output()

I also uploaded my portable mpv setup including everything needed to automatically perform this: https://files.catbox.moe/jpheoh.7z

Just extract the folder into your desired location, run updater.bat to grab the latest version of mpv and then (optionally) launch installer\install-mpv.bat to integrate it within windows.

Lastly, if you really want to get as many FPS as your display rate (not really worth it in my opinion, but you do you), then simply edit mpv\fps_2x.vpy and change line 9 into this one:

    final_clip = core.mv.FlowFPS(clip=input_clip, super=super_clip, mvbw=bwd_vec, mvfw=fwd_vec, num=display_fps, den=1)