So after a bit more time mulling the fight over and getting a night's sleep, I have a few more thoughts on the Ropalolyst fight overall:
Conceptually, I really like the direction DE are taking boss battles. Having patterns to suss and light environmental puzzling feels good, and having challenge that can't be inherently trivialised my minmaxing is IMO a huge step in the right direction for what should constitute high-level content.
Where it falls down however is, unfortunately, execution. Quite apart from the current bugs which I'm sure will be ironed out in the coming days, the whole thing just feels like it needs a bit more polish. At the very least, some textual prompts in the style of The War Within / Kuva Flood would be incredibly helpful for newcomers trying to figure out the flow of the battle, but more than that, I feel like the Ropalolyst itself could do with a good deal more visual info regarding its state. Does its shield need depleted with a void weapon, or is it just in an invulnerability phase? When should it be considered vulnerable to being grappled (random quips from Alad V aside)? Further to that, there were a lot of random shield depletions, magnetic damage, stunlocking, nullification, ability locks, one-hit kills etc that came out of absolutely nowhere. I'm sure maybe they were telegraphed by something at some point, but I feel this leads back to one of Warframe's ongoing problems, which is that there can often be so much visual clutter it can be difficult to figure out what is going on during more intense combat.
I want to love this boss and I hope DE iterate further on its mechanics going forward, but it currently replicates a whole bunch of bugbears that have plagued the game for years.