Infinite Duergar Assassin/Gloomstalker (IT WORKED!)

Update Note: Never played Durge before this post/comments and had no clue Mantle was a thing. This does give you an option via the hireling to RP as you please, and also has evidence that you can end combat and avoid HP regeneration of the enemies, so that's something?

I previously posted a thread about an infinite Duergar Assassin Gloomstalker I was trying to build out using a specific Ring to abuse Duergar Invisibility. That build didn't quite work, BUT I kept thinking about it and think I have figured it out. Testing today confirmed that you do not need the ring, you CAN beat enemy healing after combat ends, but there is a very specific sequence and timing that is almost skill based to do it.

Build: You could drop the extra Assassin level for something else, maybe War Priest for another attack? Actually, that's probably the best way to do it, but it's safer to keep the Bonus Action for Cunning Dash to avoid Detect Presence.

5 Gloomstalker 6 Assassin 1 The Great One

Feat 1: Alert

Feat 2: ASI on Dex

Equip: Max range Bow/Crossbow, Melee strongest Finesse weapon you have, initiative boosting gear, damage boosting gear, movement boosting gear.

Strategy: Go invisible via Duergar prior to combat. Initiate combat with a strike. Assassin Alacrity will recharge your action and you'll enter combat with Surprise. Use Dread Ambush attack. Use extra attack if available. You should now have 1 Action point and 1 Bonus Action point available. Cast Duergar Invisibility. Use Cunning Dash. Move AT LEAST 10ft from your initial position, or else the built in anti-sneak skill Sense Hidden Presence on what appears to be ALL enemies will find you. End turn. On controller, I now immediately open the menu ring and hover over Turn Based while the enemy proceeds with their turn. With mouse/keyboard just bind something to Turn Based mode and get ready.

At some point an enemy will go to your original location, cast Sense Hidden Presence, and fail. The moment that occurs, there is a split second where you can go Turn Based BEFORE the enemy healing can be processed by the game. On controller this is easy to see because the Turn Based icon will become active. It will look like the enemy has healed, as the animation will appear, BUT the enemy will not have gained the health points yet. You can now repeat this process ad infinitum to destroy entire squadrons of Flaming Fists in Act 3 solo, which is what I've tested this against so far.

I would LOVE to see more people test this out and see what everyone thinks. You could start as early as Act 1 as all you need is the Assassin subclass and be a Lv5 Duergar for it to work. The rest of the build just ensures you are safe from harm, always act first, and deal more damage to reduce the amount of cycles needed to kill everything. Since there is a Duergar hireling, pretty much anyone can test this too, so I'm really hoping to get some more data and opinions. Right now, I'm flipping having a heyday in the Market murdering legions of Flaming Fist, but I'm hoping it works similarly across enemies that don't have See Invisibility.