There are other ways that the automatic behaviours of these support cruisers (such as the Hoshiko's EMP and both abilities of the Domina) can be improved.
For example, the autocast could be given a range constraint in addition to the target prioritization, so that they move with the rest of the fleet instead of flying off to do their own thing. (Changing the engagement distance for these ships do not seem to fix this, I even see Iconus Guardians flying across the gravity well to give some corvette the shield link, not optimal)
During an intensive battle you're more pre-occupied with capital ship micro and focus firing, therefore the autocast and behavior of support cruisers should be smarter and more optimized in order to make them more useful.