I have never seen interceptors disengage automatically at some point after they get hit (OG, OCX, OXCE). You have to disengage manually.
The main thing the attack mode affects is whether the interceptor tries to keep within the range of its longest distance weapon, shortest distance weapon or try to close up right down their throats. The mode also affects several other things under the hood, such as the firing rate, but in essence the most important thing is the distance it tries to keep.