@lmorace the best way to test your theory is to build yourself a lab setup and confirm that it works as you expect it to.

All the Catalyst 91xx APs are designed to work in lightweight (CAPWAP) mode. As David says make sure you order the correct part number for factory installed CAPWAP software.  If you order the EWC version then it comes pre-installed with EWC software ...

So as per the other answers - they WILL work.I agree with @Karsten Iwen that as a temporary measure it's probably ok, but I'd get those switches upgraded ASAP and it would still be better to upgrade the switches first.As per the data sheet: https://w...

Agreed with @Rasika Nayanajith - don't waste another minute on 17.3.4c!  Upgrade to 17.9.4 before you do anything else.If you insist on using internal DHCP (which is not recommended as Rasika said) then take note of the best practices guide:https://w...

DHCP proxy only applies to the old AireOS based WLCs which are almost end of life.  If you are designing for future then you should be looking at the 9800 series WLCs. If you use 9800 series WLC as per the Best Practice guide (link below) then you sh...