Please have a look here. It’s complicated.
tl;dr:
- Older than installed : NOT RECOMMENDED (reading stuff and altering config files is O.K., but a fsck , resizing a filsystem and LVM actions etc. should be avoided)
- Same as installed : RECOMMENDED (theoretically the best)
- Newer than installed : RECOMMENDED, but may expose issues in niche cases, which might be avoided by directly upgrading to the SailfishOS release (or any newer one) the recovery image was from
Unfortunately the official statement is still the same (EXACT same version only).
Also maybe one of the torrents here can help. If you go this way I’d appreciate feedback about it being seeded or not.
HTH