Previously I would very patiently stealth through this section but the absurd amount of critters now makes this approach basically impossible without a lot of save scumming and luck since on top of the increased numbers Roderick has a penchant for attacking the critters on his own and him dying means automatically a reload since you cannot escape from the island without him. What is even more hilariously stupid and immersion breaking that in real time the PSI beetles tend to no use PSI at all and just rush to him in melee. It bums me that the Silent Isle is now basically a combat exclusive area.
For what it's worth, though I *sometimes* have to load once or twice (the Captain can get randomly engaged over his head, luck does somewhat factor in) it is very much possible to regularly one-shot (no save/loads) (with stealth builds) under level 10. Do you have interloper and optionally some cheap ninjatabis with +speed or other initial stealth gear (and maybe an Agility steak)? Are you using adrenaline in the "safety" area near the crystal room transition for a quick grab? Are you using combat-controlled stealth movement to your advantage (it freezes enemies in place if they don't see you yet)?
I have *never* used damage-dealing to complete Silent Isle on Dominating and I've completed several such runs now (and even more completing at least the Silent Isle...always go on the Azure bug side).
However, the way I approach Silent Isle (and the rest of my runs) is to semi-scientifically break down and analyze the geometry, movements, skills, and tactics needed. I agree with you that you can't just willy-nilly stealth the island like on lower difficulties, but I feel that that is kind of the point. Dominating *forces* you to fully optimize for what you want to do and go all-in on doing it and will still heavily punish you if you make execution mistakes. Unless I'm misremembering, this difficulty is specifically designed for people who already know the game from start to finish.
So it's in no way true that you *must* fight to complete Silent Isle or that you *must* have save/loading in order to use stealth there, but it definitely has potential for bad luck and very thin margins when stealthing.
I always take Interloper on my stealth builds though though I do not think you can find or buy Tabis before you are done with Depot A. As to "sientifically analyze movements" there are a lot of PSI beetles near the shrooms on the left side which you need to stand in to avoid the Bilocation proc, and the right side you can barely walk without stepping on a Rathound. Maybe you are just that much better or you abuse turn based mode a lot to get through it but with sensible gameplay I do not see a reliable way to get through it on a regular basis without reloading and/or without fighting.
What is the actual difference between hard and dominating now, other than dominating having higher stats? Are the numbers and types of enemies different too?
I'm asking because I think I want the "added" (if they actually are) enemies and types, but not their higher stats.
In a nutshell "Autistic" as I call this difficulty is an explosion of effective HP and a significant increase of damage. Even more so than before you want to burst down enemies in 1-3 rounds because the chances of dying in prolonged combat is even higher now. It also breaks immersion and friendly NPCs have a hard time coping with the increase of enemy numbers, HP and damage.