This internal FreeArc Recovery records compatible with any externals compressors? Adding a very large percentage or dedicated size recovery record to the archives is against the spirit of competition when repackagers are trying to achieve the smallest possible size.
Last FreeArc supported very tiny 0.01% recovery records adding the archive. (Negligible size, even for large repacks.) See the attached picture.
It is worth reading this, written by Bulat, and also the explanation linked in the first post of the topic, regarding the XZ/LZMA2:
https://encode.su/threads/2631-Xz-fo...ll=1#post50780