With the introduction of immersive mode, the hiding hud works better than ever, but I see a lot of space to improve its personal customization. While the immersive mode as a whole is great, some may prefer to keep specific parts of the UI hidden or always on (Objective Markers, Zone Markers, Zone Borders, Crane Controls, Fuel Tanks and Engines, Notification Pop-ups).

The layout I'd propose for each button:

Hud Mode <Always On|Hidden|Immersive|Custom>
==Another section (like you got with advanced video settings)==
Hud <Always On|Hidden|Immersive>
Objective Markers <On|Off>
Zone Markers <On|Off>
Zone Borders <Always On|Hidden|Immersive>
Crane Controls <Always On|Hidden|Immersive> 
Fuel Tanks and Engines <On|Off>
Notifications Pop-ups <On|Off>

Immersive variant in case of Zone Borders (the one player sees on the ground) would just keep them hidden until player gets closer to them (just like Objective/Zone Markers work by default).
Probably the immersive settings could also affect Objective/Zone Markers to appear when being even closer to the zone than it is by default.
In case of Crane Controls, the menu would remain hidden until player either uses one of the crane's actions, or reveals hud (by default on PC - button "2").
Fuel Tanks and Engines in "ghost-ly" form are seen when activities related to fuel and engines are performed, would be nice to have them disabled.
Notifications would be all the pop-ups about player(s) leaving/entering garage, recovering, taking tasks and activating missions, getting rewards and connecting with sessions.

I may also propose alternative layout that bases on setting one of three main hud modes and defining them with checkboxes, but the first idea seems to be more flexible.

Hud Mode <Always On|Hidden|Immersive>
  Objective Markers <checkbox>
  Zone Markers <checkbox>
  Zone Borders <checkbox>
  Crane Controls <checkbox>
  Fuel Tanks and Engines <checkbox>
  Notifications Pop-ups <checkbox>

and excuse me if my feedback wasn't addressed clear enough, it's quite late here and I might rewrite it

First of all let me say Thank You for the Immersion Mode feature. Very much appreciated.

Works great so far, love it.

Suggestions to make it better:

1. No Glowing Green Fuel Cells when zooming the Camera in closer.
2. No Saving Icon when game is auto saving.
3. No white X at winch connection point on the towed vehicle when towing another vehicle.

Basically, there should be no icons or glowing anything when in Immersion Mode.

Thanks again for this feature and the hard work y'all put into this great game.