Reeeeally cool idea! Well done OP!
I think you are searching for the One Shot focus mode. In that way it doesn’t matter where you set your focus point (in this case the center) it should stay there and focus every time you press the shooter button. Like other comment said it, there is more “advanced” ways to personalise the way autofocus works but this should solve your problem for the moment :)
This article explains the focus modes in a easy enough way:
https://www.morethanasnapshot.com/blog/2023/6/7/how-to-use-the-focus-settings-on-the-canon-r50
I hope it helps.
I think you answered your own question. Is it worth it for you if you “just” use it for what you mention? I don’t mean to be rude, it seems that you have a very clear idea of what you can and can’t do with it.
Could you tell me what flashlight and multitool you got?
Thank you!
That is so cool! Installed on a S23 Ultra and it works perfectly!