With this year's stream fortress, one of the new maps, marshlands, has a spin on king of the hill. In the middle area, there is a flag and holding it counts as controlling the KOTH point. As a softer form of dynamic objective from game modes with CTF and player destruction, I think this could work in comp. The advantage of a movable point is constrained by wall hacks on the carrier and limitation of their movement from the whole map to a small area more easily played around by the other team.

Update: With the permission of the maps' developers, I have created a alpha version of HTF_Ashville. Now looking into doing testing. https://tf2maps.net/downloads/hold-the-flag-ashville.20486/