The blank look might mean you've surpassed their knowledge with your question. The less cold line after the pressure drop under the hood, the better, I would think. Remember, Mercedes is about effeciency.
Yes, those are orifices that get clogged under the hood. Somewhat easy to change.
I once had a Mark V Lincoln with the suction throttling valve setup that was supposed to keep the evap pressure at something like 21 psi. It would often clog & freeze up. Paul.

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1984 300CD red/blk 290,000 partial resto
1980 240D 4 sp Brn/palomino gone
1997 Mazda Miata STO edition wife's baby
1988 Lincoln Mark VII LSC next resto
1986 Subaru GL wagon daily
1993 Isuzu pickup field beater
2008 Honda Civic EX-L 5sp wife's new car
1978 Honda XL350
1974 Honda XL70 my Calif. ride in HS