Found somewhat of an answer to my question in another post. Though, it says “v5.1 will fully support for sending large files (up to 1gb) in the mobile apps.” I’m running v5.1, and when I send a photo via signal it’s size is reduced by ~50%, and via SimpleX it’s size gets reduced by ~75%. https://simplex.chat/blog/20230301-simplex-file-transfer-protocol.html