Encoding with Vapoursynth + Avisynth

[Selur]

But to get back to the original topic, do you think it would be possible that Hybrid switches from Vapoursynth to Avisynth (or vice versa) during encoding, for example just before output is generated on the script, the video would be reloaded into an avisynth script and further filters would be applied ?

You mean that Hybrid does a multipass encoding, first for example, it uses Avisynth to filter the source, saves the output into some lossless compressed file, then uses Vapoursynth to filter that output and encodes it to whatever output was chosen?
Sorry, no. Hybrid atm. does not support this, and rewriting Hybrid to do this seems too much work for the gain.

Cu Selur