When coco dries the EC skyrockets. If it dries a little, the EC goes up a little (and vice versa)...So some dryback won't be that noticeable. I've been experimenting with this by using 1.5 g, 2 g, and 3 g pots all fed twice per day. The smaller pots get substantially more "dryback" but it's still not enough to derail them...however, they yield less than the bigger pots, simply because the larger root balls are exposed to a more idea concentration of nutrients at the root zone for longer AND also a bigger root ball means more surface area exposed to and collecting nutrients. The whole point of multifeeding in coco is to constantly refresh the nutrient levels at the root/soil interface.
Another factor is the EC you start with. If you run "low ec" (around 1) then you might not notice much tip burn or other leaf issues as you would if you run a "high EC" because the peak EC will be lower if it starts lower to begin with. This is why you can get away with pretty much as much dryback as you want with seedlings being fed very low ECs-letting the pots get light and even visibly dry, doesn't really hurt them because the peak ec at dryback never gets too high, and a wet/dry cycle helps fill the roots out.
As for what is ideal, studies have shown about a 20% increase in yield when going from 2 fertigations per day to 5 fertigations per day. So setting up an automated system and keeping that fully rooted media fertigated 5 times per day does increase yield by keeping an optimum concentration of nutrients in the root zone at all times, BUT...it's 20%. For a commercial grower, it's a nonstarter, I would absolutely keep the media more moist with multifeeds 20% is huge commercially...but at home, I'm happy with 2 feeds per day for plants that have filled out their containers with roots. I never multifeed until a transplant has a full root ball.
Keep in mind fiber length of the coco you use too. Fine fiber coco holds much more water (and much less air) than longer fiber lengths. Fine fiber coco is manufactured to mimic peat much more closely. I see new growers have trouble with seedlings all the time in coco, and it's usually down to overwatering in fine fibered coco. Of course, any difference in how you treat a plant based on the fiber length of your coco disappears once the roots fill out. Perlite makes zero difference if your coco is medium to long fiber already, and with short fiber you could add some perlite and lower it's ability to retain water....but why not just buy different coco in that case or simply make watering adjustments until the root ball forms? Any coco is easy to adjust to once you know it's characteristics.