This is a high effort filtering and encoding for Champignon no Majo and should be the best version you can get right now.
slow.pics compare: https://slow.pics/c/h16Epbs2 (episode 01 to 03)
Additional improvements have been discovered in the encoder that helps with texture retention. Texture retention in episode 04 onwards should be even better than the compare above.

For filtering, the main episode is descalable. We descale the main episode using vsscale.Rescale, and then we write a custom akarin.Expr to carefully dampen the sharpness of the descaled image. Thanks to many people in the JET server such moe teaching me the method, we fully recover the layer of 1080p texture on top of the image after descale.
The OP and ED of this anime is not descalable. Instead we use a stronger vsTAAmbk.TAAmbk to deal with the OP, protected by a custom akarin.Expr taper. And we use vsaa.based_aa to perform aa on the ED.
Also, as usual, before the aa, OP from multiple episodes are merged using vsdenoise.frequency_merge.

For denoise, the main episode doesn't quite need a denoise at all. Instead we only use dctf.DCTFilter to clean up some slightly annoying checkerboard in the source.
For OP and ED, we use the typical vsdenoise.mc_degrain → vsdenoise.bm3d → vsdenoise.nl_means to stabilise dynamic noise.
At last we apply a very conservative dose of vsdenoise.DFTTest before sending to the encoder.

This anime has this layer of texture on top of the image, which is really hard to encode.
We use the very latest version of 5fish/SVT-AV1-PSY for this encode, and we squeeze out every bit of potential of the encoder for this encode.
This is the full encoding parameters: --preset 2 --crf 29.50 --tune 0 --scm 0 --noise-level-thr 16000 --chroma-qmc-bias 2 --balancing-q-bias 1 --balancing-luminance-q-bias 7.0 --balancing-r0-dampening-layer -3 --enable-variance-boost 0 --qm-min 9 --chroma-qm-min 11 --noise-norm-strength 4 --ac-bias 3.0 --variance-md-bias 1 --variance-md-bias-thr 5.5 --complex-hvs -1 --dlf-bias 1 --dlf-bias-max-dlf 6,2.
Specifically, apart from the usual parameters, we use --balancing-r0-dampening-layer -3 to control the filesize. And we use --noise-norm-strength 4 --ac-bias 3.0 to try to fully retain the layer of texture on top of the image.

Thanks to all the people creating the tools, plugins and vsfunc's that make this possible, and thanks to everyone in the community for teaching me, pointing out issues, and giving me advice.

If you're interested in AV1 encoding for anime, you are welcome to join AV1 weeb edition at https://discord.gg/83dRFDFDp7.

You are welcome to do anything with this encode, including remuxing and republishing it. However, we would ask you to leave a credit to Kekkan if you can.

We recommend using MPV to playback our releases. Thank you for seeding after download.