How to configure cloud backup for Time Machine and Apple Photos on SSDs?

Time Machine backups are stored specially formatted external drives. Whether its possible to back that up ro not, is generally a question for the backup software.

There's nothing preventing the software from reading the external drive and backing it up, but moving it out of the specially formatted external drive is likely to corrupt it and not be able to be restored so Time Machine can use it again. In that sense, yes it's probably not recommended to back it up, though it may be technically possible.

For the Photos Library, you can move it out to an external drive, and again the backup software for iDrive may able to backup the library file and restore it. Though if it's kept on the internal drive, Time Machine would almost certainly already have it backed up, making it technically unnecessary.

If you want to have a backup for Time Machine, then just plug in two Time Machine drives. They'll both work, and you get two independent backups. For my MacBook, since I don't have TM plugged in all the time, I sort of alternate which one I plug in.

I also periodically drag the Photos Library to another drive. I also do other totally redundant things.