https://github.com/gorhill/uBlock/wiki/Resources-Library#href-sanitizerjs-
https://github.com/gorhill/uBlock/wiki/Static-filter-syntax#urlskip
Example on (a sort of nsfw) https://figure-times.com/: https://px.a8.net/svt/ejp?a8mat=2TMZ7K+6IKXR6+NA2+BW0YB&a8ejpredirect=https%3A%2F%2Fwww.amiami.jp%2Ftop%2Fdetail%2Fdetail%3Fgcode%3DFIGURE-182418 here https%3A%2F%2Fwww.amiami.jp%2Ftop%2Fdetail%2Fdetail%3Fgcode%3DFIGURE-182418 should be converted to https://www.amiami.jp/top/detail/detail?gcode=FIGURE-182418.
If possible, can you consider adding -base64 as an alias of base64decode? I will be much appreciated if I don't have to add separate filters for AG and uBO, or to open an issue ticket in FiltersCompiler.