I think I found a good solution, using this answer by ncw as inspiration.
I mounted the remote with appropriate settings, such as setting vfs mode to full and setting the max age to a large value. Equally important, I set the max cache size to the size of my disk.
Once mounted, in another session window, I use
rclone hashsum crc32 /path/to/mount --exclude-from filter.txt
This outputs the hash. The files are downloaded to the cache as a side effect. By supplying the same filter/excludes file i use in my final move command, only the files I want to move are cached and primed.
Last step is to start the move, using the local mount as the src.
The only thing im not sure how to configure is the order for the hashsum is not the same as the order of the move operation. So for a short while, the hashsum could be caching some files and the the move is working on other files. But at some point, im going to get the value of the cached files.
@ncw any recommendations on how to make sure im caching and moving the files in the same order to get the most effective use of it? @Animosity022 you too. You're pretty good with manipulating files and orders.