I downgraded from Eris 5 to 4.5's last year, just because the 4.5's were very cheap (used), and I want to add some other monitors eventually (currently also have a single Mixcube).
The 4.5's are definitely missing lows, but beyond that they are pretty balanced and pleasing to use.
No regrets at this point. I use them at low to moderate volumes, as well.
If you can go bigger like 6 or 7 or 8 inch woofer class speakers, you will probably gain a lot of lows.
Also, the Eris E5's were only SLIGHTLY bigger than the 4.5's, and have that front bass port instead of the back, which might make a difference placement wise? Also the E5's each have amps vs the 4.5's where one amplifies the other (which makes the 4.5's lighter if you need them to be portable, ever).
Anyway, if you have headphones to hear below like 80hz, you will like the 4.5's.
(Nobody cares, but I want to also add APS Klassik 2020 and maybe a used BlueSky MediaDesk 2.1 setup to my Presonus 4.5's and Mixcube).
Kali audio is probably a great choice for more lows, looking at your list (not familiar with most, though).