If you want to load just the panel memories of a song that had been saved, go to page two of the load menu and turn off everything but Panel Memory. That will load just the panel memories and leave everything else alone.

Quote: "if I hadn't made any new save, would this have brought back all the Panel Memory settings if just reloading the Sequencer only?"

If you load only the Sequencer file (the.sqt file) you will not load panel memories. You need to load panel memories as above.

You will only have a problem with sequences that use custom memory if something had been done to change custom memory. But that is bound to happen eventually over time. In addition, if you want to send your sequence to someone else, they are unlikely to have the same thing in custom memory unless you also send your custom memory files to them as well.