Depends on number of calcs but for me I found that around 4-500 and the tablet starts to struggle with memory. Older versions of 123 the app would just shut down on us.
What I do it split it into several forms and then relate them all to a main point. One reason is we can have multiple users with multiple tablets on the same site. Not sure if that would work for you. My workflow for that is here https://community.esri.com/thread/221263-mapping-with-survey123-within-a-polygon-or-admin-unit
But first some ideas to help the load.
Are you setting the bind::esri:fieldType to null for all intermediate fields that do not need to be stored in the data? I also wonder if you can create a view with less fields and then use that for the power automate.
Are you breaking the form into groups and adding relevant to these? That way the entire form does not load all at once. Esp on the pulldata these do not need to load until a value is picked. I have found that pulldata tends to recalc a lot also.
Are you using once() or calculationMode=manual or whenempty where you can?
Are your lists external using select from file or the search appearance?
Do you have newer tablets with lots of free space? Also are they higher end? We have tested all the iPads and a iPad Pro loads significantly faster than a regular (and an Air is in the middle). Only time we had speed complaints we found out teams were buying older gen model refurbs that were sometimes 5+ years old (which with Apple's crazy naming is easy to do).
If you can post a version of the form that would help.
Hope that helps
