reasons why this ability is op / needs to be removed:
1. Allows the bofors to counter its counters in the early and mid game (Mortar + AT Guns + IG) which is suppose to be the mortar pits job
2. Destroys ambient buildings in literally 2 seconds (you have no time to react if you have guys in it)
3. There is no warning so you actually cant intentionally doge it.
On the other hand - name any other unit that is perfectly countered by a single mortar/AT gun/ISG. And I mean perfectly. Even a conscript can run from a king tiger - a bofors is stuck wherever you place it.
The building thing needs fixed.
There's the sound of the bofors firing. Likewise there's plenty of time to retreat or move after the first volley.
Honestly most people that get caught out by this tend to clump up way too much. Attacking a bofors with mortars? Well don't stack them on top of each other.