Your comments

yes, read once write to multiple destinations all at once and then verify them all them = would be perfect

Teracopy for linux would be so cool.

Would be perfect if it could extract multiple checksum formats:
1. single file / same name, different extension - like: md5, sha1, hash

2. search for per-folder checksum / same name as folder and is inside of the folder, different extension - like: md5, sha1, hash

3. search for root-level checkum file and extract checksums from them  / located on the upper levels of folders

4. Mix all these options to extract as much checksums for verification.

5. Select what format to search for and use exclusively - md5/sha1/xxHash64/??? if not found then generate new in this format and use it for verification.

Would be super cool if logging where to be added to indicate what options where selected and write the checksum data in the report indicating if it was extracted from existing or generated. This would then make it more competitive with shotputpro, keka and some other tools that the film people use...