Received the Silicone Vacuum Hose I ordered in four different sizes. https://www.siliconehose.com/silicone-vacuum-tubing/

In the process of replacing all the cheap plastic vacuum tubing and old rubber hoses with silicone vacuum hoses.
Plans are to re-route the vacuum straight from the brake booster connection across the top of the engine to the little vacuum reservoir at the turbo modulator.

Dash items will still use original routing but will separate from the turbo supply.

This is pretty much what I did. Ran the hose behind the fuel filter head from the booster, on to the T-fitting at the firewall on the passenger side, then on to the turbo vacuum reservoir. There were a couple of disused plastic mounts under the front valance; zip-tied the hose to them to keep it up as far away from the head as possible. Also, anywhere there was a join, it got a clip.
I'll see if I can't get a photo of the routing over the top of the engine tomorrow. Unfortunately, as I used black hose, there likely won't be a whole lot to see, but the zip ties are fluorescent so should be able to give an idea of how things were run.

This interests me as I really don't like how the HVAC controls feed from the turbo vacuum line. Definitely looking forward to what you come up with for this.

Finished this evening. Plan to test drive later. Silicone hose is MUCH tighter on all the slip on connectors.

Installed "Tee" at brake booster for new vacuum line directly to turbo vacuum reservoir.

Black hose is original rubber hose that now only feeds HVAC. I may replace this hose as well with silicone, but will have to order some more hose.

Removed "Tee" on firewall where vacuum line goes inside to HVAC controls. Replaced it with a straight connector. Close quarters to work in!

Routed new silicone vacuum hose across top of engine over to connection at vacuum brake booster. Not worried about "Heat" since it is silicone hose.

Nice!

See pictures posted in first post of this thread for reference to all of this.
OK, mine had a one-way valve at about that spot in the hose routing. Did yours, and, if so, did the tee eliminate it? Any differences? My suspicion is that it's there (mainly) in case of failure at the HVAC line.
The only "Check Valve" I found was in the vacuum line where it connected to the plastic tubing transitioning to a rubber hose that connects to the turbo vacuum reservoir.

Planning on doing this as well, but have to build up the enthusiasm to crawl under the dash first. That T-fitting on the firewall where the HVAC controls get their vacuum from is no fun to work with, either.
Replaced that "Tee" with a straight connector and eliminated the "Tee". And yes it was a PITA to get at. Cut my hand while eliminating the "Tee" at that location!

If I'm understanding correctly, you're not feeding vacuum to the HVAC controls right now. Is this correct?
NO, still feed vacuum to the HVAC controls via the original tube but did eliminate the "Tee" fitting where it connected to the plastic tube going through the firewall. Plans are to replace this piping with silicone when I get some more silicone hose in stock. Plan to add a small check (one way) valve in this line as well.
And yeah... Trying to fiddle that thing into having all three lines properly connected was not fun.
Now only have a single straight connector there instead of the "Tee" so there is only two lines connected.
FWIW, I'm also planning on replacing the main feed from the vacuum pump to the brake booster with silicone, but need to order more hose for that.
Not a bad Idea, but it is a pretty robust hard rubber hose I believe it is 3/8" size.

This looks like a worthwhile mod! WW, do you have a parts list - tubing sizes/lengths, fittings/connectors?
I'm guessing the issue of where to use each size will be pretty obvious once I get into it.