Pre-requisites : What allows you to be able to navigate to a step? If you can do steps out of order (navigate to any step - https://powerusers.microsoft.com/t5/Power-Apps-Ideas/Navigate-Web-Form-Steps-out-of-order/idi-p/4927...) but you shouldn't be able to get to a step X until steps A, B, and C are complete as step X depends on the A, B, C. Maybe Step X summarizes A, B, C, and allows a user to re-validate the information they have in A, B, C.
Completion Conditions: What makes a web form step be completed? Is it the required fields or is it a series of other conditions? Can a calculated field be used as a completion condition. Does X + Y + Z sum to greater than 100. Does a sub grid have X number of records populated?