Like you I'm now just a humble GA pilot and during my flying days sat in the "boot". I had to add the caveat to avoid the banter from the pilots on the Forum.
A picture always helps. In the Falklands we intercepted the Tristar as it approached the islands . Some of the cloud down there could be quite thick and this short clip is fairly typical. You can see the differing density as the Tristar drops into the tops. It disappears for a short while but reappears quite quickly. At that point, the lead pilot needs to be predictable and hold a steady heading. A turn towards could be instantly dramatic whereas a turn away would be a guaranteed lost contact. In formation with a like type there were known formation references which made life easier (in the F4 it was trailing light on the wing tip lined up with the blowhole and stab tips squared off). Formating on an unfamiliar type normally meant that the formation position was looser so losing contact was a greater risk.
Like others, it was rare to have to break out but we probably got more nervous in the back than the guys in the front. More than a healthy few seconds of lost contact caused a certain "pucker factor"! In an aircraft fitted with an AI radar it really wasn't worth the risk if the other aircraft disappeared. Turn away, time the diverging heading, turn back and lock up on radar. Once in trail, you could close back in using a visident profile or just stay behind about a mile astern.
