Just since I read the thread from the start I will add my 2 cents, I dont think you can overwater with chunky coir and perlite, Ive literally tried
When I grew with bricked coco/perlite I started out waterring when the pot felt light, just as I was used to with my previous years of soil growing, they dry out a little faster than soil and the plants do ok and youre happy, but just like I read in this thread, someone really hit it home with me to try multiple feedings a day so I setup an easy drip to waste setup because I didnt want to hand water multiple times a day and I was stunned by the growth in veg, its like the plant wakes up and takes off, I was a T5 cfl grower at the time and you really have to stay ontop of the plants growing into the lights if you forget to peek for a day
BUT, then my lazyness / easy going personality steps in and where I fell out of love with coco is how much water you now have to make, and how much time you have to spend with the plants almost daily and really staying ontop of the PH, I ended up choosing against coco because I like to walk away from my setup for days at a time, and I didnt put enough effort into keeping the nutrients and PH in check.
Ive settled on autofeed hempy buckets with promix. I can make a 25 gallon res of water and walk away for 10 days, works for me and my life and Im ok with the plants growing "a little slower"