Gardener access

I’m not sure this post belongs in the hardware section, but I could not find a better place.

I’m interested in converting my sprinkler system to use open sprinkler PI, but I’m concerned about how the gardeners would use the system. I think they normally test the sprinklers, and sometimes tweak the programs (I don’t know much about gardening or gardeners). I think I would be ok for them to just let me know about zones needing more or less water, but I they probably need to manually turn on and off the sprinklers to test.

I’m not sure how often they would need to tweak the program. I would hope that the controller is smart enough to not need constant tweaking of the program.

Ideally, I would like to place the controller inside the garage to get it out of the weather, and the gardeners don’t have access there. I see that there is some development of attaching and LCD to the controller, and that could solve my problem if it’s pretty intuitive to use (and if I put it outside).

My initial thought was some sort of remote control, but that might not be a great idea and they will probably not know how to use it.
I’m fine with leaving an old phone or tablet in a box outside for them to use, but I think it’s going to overheat. I don’t think I can rely and them using their own devices and data, and remember how to connect to the system as the crew changes.

Does anyone have any experience or ideas in this area?