Thank you for this. I enjoyed every bit of it. The filtration on your tank sounds great. I was going to ask about the roselines because they are shaped to be swallowed by the cat rather easily.
Our bolts did not bother anyone either (except each other from 3" right out of the bags, a minute into the acclimation) for a long time but after reaching around 12"-14", they became far more territorial and would chase almost any fish away from their end of a 240 gal. I wonder if you'd observe the same later on.
You say you had 3. Together? I think no way. I was only able to cohab our pair in a 4500 gal and even there they'd meet up for regular fights. This is no way to keep them, no matter the tank size.
Good appetite and indifference to light I also observed, so that's good and consistent.
I'd say ours were hardy. As for the price, wow, that's expensive indeed... but I am going on purchasing my pair in 2015 from Ted's Fishroom at $90 each at 3".
Here is my thread on them.
https://www.monsterfishkeepers.com/...-2-years-old-in-4500-gal.683454/#post-7693793 Sadly, I've lost both, at adult 14"-16" sizes, one was too aggressive in a 240 gal to its tank mates and I transferred it to what I call a "jerk tank" hoping it would cope but it couldn't and I made a huge mistake of not being around to catch him getting whooped first class. The other one seemed to have contracted a columnaris or some such in 4500 gal at the time that I was having this infection wiping out many fish in my tanks over 6 months, back in 2018.