this combo technique sounds useful, is it something like reviewing memory palaces with spaced repetition, instead of reviewing standalone information?

Something like that, yeah. The idea being that you create a memory palace or physical space, and then memorize a map or route through it via spaced repetition.

Memory palaces are often recommended for reference-type information, so I think this would work well. There are a number of discussions on Art of Memory talking about this:

https://forum.artofmemory.com/t/mind-mapping-memory-techniqu...

https://forum.artofmemory.com/t/anki-to-load-up-a-memory-pal...