So, love the new colonization system. It's a lot more modular, and presents the player with a lot of interesting choices with regards to what buildings to construct first. I do think that it's later start is a bit of an issue - colonies are important locations to re-supply and deploy new units from, and requiring that you raid Liyue Harbor before you can begin setting those up is an issue. Particularly when you need to build the slave buildings to keep up slave production... and those all require a fairly sizable population of that slave to being construction. Overall though, I think it's fine? The information we get from the first upgrade is incredibly important.
My issue is with the expense of colonizing - colonies cost a lot more Abyss Branches to setup a portal than they did previously, while those are also a lot harder to produce. Wedges and Branches no longer increase your Abyss Power, and at the same time sacrifice's efficiency has been reduced (1:1000 basic now, instead of 1:100). Which means the only real source is from destroying statues, which are a limited resource and result in you capturing more heroines in order to do. Likewise, it seems like the cost of various buildings and upgrades have been increased. So you need more items produced from Abyss Power, but you have a lot less of it available for crafting. And there's also another knock-on effect for this; Since Nycto Resonance was changed to be based on our remaining Abyss Power (instead of total), it's a lot harder to get high Nycto Resonance. Which means it's a lot harder to get access to our advanced Nycto units.
I do feel like it makes sense that the items no longer directly provide Abyss Power, as with the new colonization and farming system they are a direct resource for providing power to other features. However, I think that this chance means the related systems could us a bit of a re-evaluation. Like; maybe the cost of these items could be reduce, and switching production shouldn't remove current construction progress. The Branch and Wedge simply aren't as versitile as they once were, so should they still cost 100 and 500 to produce? And since production does carry over now, does it make sense to discard the current progress whenever you switch what you're spending your energy on producing? You do need both branches and wedges to finish colonization, and with how long it takes to connect up new colonies, wedges are particularly needed to keep your army re-supplied.
As for Nycto Resonance, I wonder if it might be better to base it on our current Abyss Power, as it was originally? With less sources of Abyss power, I don't think it'd be unbalanced. Alternatively, maybe we could get some more thematic sources of Abyss Power? Maybe corrupting heroines should boost our Abyss Power directly, not just remove the suppression requirement. Or maybe a way to harness the "abyssalfication" of the world to directly boost our availible Abyss Power.