I would probably create the number of user specific boolean columns as you need for each instruction on each sheet. Then add a text component with the specific instructions you would like to add, along with a checkbox component pointing to the respective user specific column. Once a user reads the instructions and clicks the checkbox, you can set visibility to forever hide the text and the checkbox. This of course works best with some sort of user sign in. Otherwise in a public app, the instructions will reappear when a user closes the public app and reopens it. Setting to Public with Email, for example, will allow the checkbox values to be saved and they will never see the instructions again after they acknowledge them.