Once you toggle and request an update to 26, it takes a while for it to download and do the actual install. During that period, you can stop the install with no damage using what I described. I did that on an iPhone.

I went ahead and did the update to 26 on an iPad and about half my daily driver apps are borked, especially when it comes to resizable windows under multitasking.

Once installed, the only way back is to to hard reset and restore from iCloud backups. Big pain. Here’s a guide on how to revert: https://www.redmondpie.com/how-to-downgrade-ios-26-beta-1-to-ios-18.5-guide/amp/