I can’t find any time-related clause other than the instance-related clause above.
However, for each of the family members on my Max/Family plan with Travel/Phone/Breakdown, I can remove them in 2 ways:
Remove them from Breakdown Cover
Remove them from All Cover
So family members either have travel/phone/breakdown insurance, or travel/phone insurance, or nothing. It seems you can’t have travel/phone without phone/travel.