There is no need for you to test, I installed trial version of XYplorer and it do not integrate completely into Windows 10 file explore, it only replaces some parts.
Mainly here is how I tested:
1. Double click on My computer icon on desktop -> Windows file explorer opened
2. Right click on Any shortcut icon on desktop or in Start menu -> Open File Location -> Windows file explorer opened
3. Double click on My computer icon on desktop -> Opened drive letter -> XYplorer opened
4. Total Commander -> Right click Open folder -> Windows explorer opens
5. Firefox -> Open File -> Quick Access -> Windows file explorer opened
I also tried Changing Registry keys and have no way to set above to open in XYplorer. Lets hope that dev of XYplorer can shred some light.
EDIT: I forgot to add that in past only way to fully customize Windows explorer is to do complete replacement of explorer as default manager (Desktop included)
For Kids I use https://www.magicdesktop.com/en-us
but in the past I have used https://www.stardock.com/products/odnt/
and also few of these https://www.online-tech-tips.com/softwa ... -programs/
(bit outdated if I find newer list I'll update)