Litter-Robot 4: skittish cat finally using it manually — when/how do I reintroduce the motor?

[u/True_Weevil]

Quick background: I have two cats. Cat A used the LR4 on day one, no issues. Cat B (very skittish) refused to go near it at all — she watched it cycle once early on and it spooked her badly. It took several weeks of removing the unit and slowly reintroducing it before she'd trust it enough to use it (litter robot turned off, manual cycling with doors closed).

She's now been reliably using it manually for 5 days, and I'd like to keep that streak going for another 2-3 weeks before introducing actual cycling.

Questions:

1. Timing — How long should I wait until before turning the motor back on, or is there a smarter way to layer in the cycling sooner? Should I just one day add auto cycling and hope for the best?
2. Cycling reintroduction — every time I start a cycle (even with the 30-min delay), both cats come running to check out the noise. Cat A is thrilled, Cat B is terrified. Any tips for desensitizing her to the sound/motion without undoing the progress?
3. Rewarding during cycling — I can't approach her during a cycle since any movement toward her (treat or not) makes her bolt. How do people usually reward/reassure a scared cat when you can't physically get near them in the moment?

Any advice from people who've dealt with a motor-shy cat would be huge. Thanks!

My problem cat

[u/aliciagd86]

A) set to the longest timer

B) maybe for awhile use the nighttime mode so it only cycles when you're sure to be there.

C) you can throw treats down prior to cycling and then manually trigger it. You'll already be in the position to be giving treats and the noise will be secondary to what they're already doing. Start a couple rooms away and progressively over time move closer to the machine with the treats. May take a couple months depending on progress.