Perhaps, saving the position in memory every 200 steps or once a limit of +90 degrees or -90 degrees is reached could be a suitable plan. However, it's worth considering whether saving the position every step of the stepper would be more appropriate.
Regarding the possibility of a power failure before updating, if the position is saved every step of the stepper, there wouldn't be catastrophic consequences. However, with less frequent updates, such as every 200 steps or at the limits, there might be a risk of losing some positional data in the event of a power failure. It ultimately depends on the level of precision and robustness required, However, I'm not prioritizing that aspect at the moment. My current focus is on making the decoder function as a limit first without faving the position in a memory. Once that hurdle is overcome, I can delve into solving the other questions. Once I've successfully implemented the limiter as required, the next step would involve saving the position and retrieving it from memory upon startup.