Herring,
No, actually the restricted orifice causes your modulator to receive a "weaker STATIC vacuum"... one that can more easily be modulated. Let me try to explain !

When I re-read the above parts of you last POST, I sense that I should explain my somewhat different way of thinking of vacuum control systems... a way that seems to help some better diagnose these systems.
Static Vacuum Systems - These are systems in/through which very little air actually moves except when the vacuum force momentarily actuates a diaphragm to perform some mechanical motion... door, fuel door, and trunk lock elements or "PODS". The vacuum modulator on the transmission is also an example... as is the EGR valve. IMHO orifices in a static only vacuum control system would accomplish very little!
Dynamic Vacuum Systems - These systems actually have air flowing through them either all or much of the time and the air flowing into and towards the vacuum source (our pump on the engine)... this provides the means to vary or "modulate" the strenght of the vacuum force in the system... or often thought of as " bleeding-off " the vacuum. For most of us the best example of this is the " bleeding " effect that the VCV introduces into our Tranny-Shifter Vacuum Control Systems. Your YR/model MB also has another dynamic vacuum component that is part of your EGR. Usually the "Dynamic" portion of a vacuum control system has a port that " Vents the vacuum " which is really backwards terminology... for the air actually enters into or through these "vents" which are usually terminated under the dash so as to better assure a cleaner source of air that otherwise (if in the engine compartment) would cause the system to clog up far more quickly. NOTE that the diagram for your car shows two such "vents"... both with an "a" label... one on the Shifter system's VCV and one on the EGR system's electric actuated switchover valve #81! Orifices I would think are primarily in and to my knowledge only in " dynamic " vacuum control systems.

Combo Static/Dynamic Systems - Yes, our Tranny-Shifter Vacuum Control System is a combination of multiple systems... the shifting part and the EGR part... and further it can be said that both of these systems have both static and dynamic components as I tried to explain above. The vacuum modulator that is physically on the transmission and the EGR valve itself are the static components... and the VCV and #81 electric Switchover Valve that is part of the EGR control system!

So let me now try to relate my thinking of how these two types of Vacuum Control Systems combine to give us proper transmission shifting. Let us first think of the vacuum modulator diaphragm that controls a hydraulic valve inside the transmission. As a " static " vacuum component, it it is "dumb" and IF it were connected up by itself as you tried, then its going to go to the fully actuated position and stay there... which would NOT help up much. These transmissions were designed to be hooked up to a gas engine with an intake manifold in which the vacuum level fluctuated wildely as the throttle and engine speed varies up/down. This is where our " dynamic " component (VCV) comes in for it's job is to translate the mechanical position of the throttle and use this to modulate the vacuum being sent to the Vacuum Modulator which in turn modulates the hydraulic valve inside the tranny.

So the VCV starts out NOT bleeding off any vacuum at all because it is shut out of the system by the switchover valve(s) that are also connected to the throttle linkages. When the VCV is first opened to the system, think of it as having a minimum " bleed " effect on the main vacuum (the power source) for the vacuum modulator on the tranny... but as you increase throttle, the mechanical linkage connected to the VCV causes an internal valve in the VCV to open more and more causing a greater and greater "bleed-off" of the vacuum being sent to the transmission vacuum modulator.

So the " main " or stronger vacuum is really that being initially sent to the modulator on the tranny... and it is the "dynamic" VCV component that is working as sort of a side-bar component to interpret throttle position and help modify or create a more appropriate vacuum signature being seen by the tranny vacuum modulator that thinks your car has a gas engine! This, IMHO, is why the German engineers devised the set of 6+ plastic orifices as a means to create what I think of as multiple vacuum pressure zones... and thus the need for the smaller size orifice in the line going to the tranny. Without this smaller opening, the vacuum being sent to the modulator would be too strong for VCV’s bleed-off effect to work (remember “dynamic” means there is air continuously flowing in there as long as the throttle is depressed). By using more than one orifice in your “combo vacuum system” allows the designers to create a strong initial 1st stage vacuum zone initially near the main vacuum line ( between pump and brake reservoir tank), and this is sent on via the switchover valves to power the EGR system… so the 2nd orifice is used to reduce the vacuum so that the VCV can properly modulate the vacuum signature. The VCV is adjustable but coming off the assembly line I’m sure that the orifices are far easier to use in making the final tuning of the vacuum level they want it to have.

So think about how air is flowing in these dynamic and/or combo vacuum control systems and you should be able to more readily diagnose problems! Oh yes, dirty orifices is why we put cheap in-line paper fuel filters on these vacuum vents or inlet openings under the dash! Once you get things working the way you want, then you put on these filters.
Regards... out of here!