"comparable" to RD88 depends on what parameters you're comparing, but if we're talking about lightweight and modestly priced 88s, ones that come to mind are Roland Juno DS88 and Korg Kross 88 (which have free computer-based editors, and also Yamaha MX88 and CK88 (which have ones you can buy from John Melas, free demo available). A good starting point might be to download those apps and check them out.
ETA: Casio PX-5S could be another possibility, And there are some Kurzweils, but their SoundTower editors have a reputation for being problematic, and I'm not sure they actually do what you're asking about, assign patches to Favorite locations. But again, you can download the apps for free and examine them for yourself.