Impressively, Mochi now offers FSRS (beta but still available in the app's main settings) and both the type of scheduler (Mochi default or FSRS) and the schedulers' settings are configurable on a deck-by-deck basis.
The developer is very responsive to folks on the forum and often quickly adds requested features.
Overall the app is well-designed and fun to use. I appreciate the swipe left/right to fail/pass cards on iOS. My one complaint is that the web clipper only works with Chrome and Firefox, but not with Safari (surprisingly). It would also be useful to have a global hotkey/palette to quick-add cards to various decks, similar to how OmniFocus lets you quickly add items to the OF Inbox.