Thanks for the feedback,
Depending the logo's sizes and types the pre and post blur parameters can really be helpful indeed, again depends of the logos but it can really improve the results, sometimes reducing values gives better results for me, really depends on logo and video material.
Same for the PPmode setting, but if i recall correctly you need to have mod16 videos to apply the mode 2 and 3, i'm not sure and will have to try again but pretty sure that trying PPmode 3 on some videos brings an error message about this.
Sharpness settings is another thing that can be played with to improve results.
When you say you changed the colormatrix to 709, you mean you edited the "InpaintFunc.avs" script file and changed something there or simply added a conversion line on your general script ? If you edited it inside "InpaintFunc.avs" file i would be interested to know where you done it please, something i did not thought about before.
As for using FFT3DGPU this is also an interesting idea, If you do push testing on this please share your results and the changes made, might bring even better results
Analyze can take some time on long (and high resolution) videos using a speed like 10 to 20 but once done it's nice, at speed 5 it's quite fast usually, mostly using speed 20 myself but never was a problem tho.
This plugin is old but for now i did not found anything doing a better job at removing logo's, strangely it is not much used
Waiting to hear from you and your experiments again,
Thank you.