Saving Configuration for all settings

[Selur]

But it still does not store/hold X264/Base/Restriction setting: Preset, always returns to "none".

That is correct. The settings are saved (command line is the same), again applying the preset doesn't make sense.

Also, different topic, Filtering/Avisynth/Line there is no Resizers, I was looking for spline36. I see only Anti-Aliasing, Darkening, Misc.
Under VaporSynth there is no resizing tab as well. There is Nedi3. Do not know how to apply splinexx resizing.

Filtering->Avisynth->Frame->Resize
Filtering->Vapoursynth->Frame->Resize

Cu Selur