Engine mounts disintegrate? How often should the EGR need replacement?

Hello I recently had a engine vibration issue so I took my 2008 3500 cab and chassis to my local Mercedes dealer (on a side note I converted my warranty from Dodge to Mercedes, best decision ever). They said my engine mounts were destroyed and came apart with ease. They replaced for a cost of approx 600$.

The reason I am posting this is because they blame the worn out parts on my heavy load. I am heavy but below my max GVW. Has anyone else had this issue? The mechanic said mine were the first one they have replaced. Could I have another underlying issue?

Also the dealership replaced my EGR again (I am on my 3rd), at a cost of $1000 I am worried that once my warranty is up this could get expensive. How often should they fail? I am using the proper oil and changing it at regular interval.

My sprinter has approx 103k KM

Thanx for all the feedback in advance

Engine torque (twist) is what stresses motor mounts. The engine in your truck doesn't have tons of it so , no, you are not causing it, the mount should be designed to handle whatever twist the V6 can dish out.

Motor mounts don't fail very often. Yours may have just been a bad pair from the factory that finally showed their defect. I doubt it will happen again.

The EGR......some replace a lot, some just clean them, some put up with the occasional buck and snort and never touch them. I ran almost 300k km and never touched mine, I just went along for the ride when it acted up.

Again, Egr valves are under engine warranty policy for 100k miles or 5 years.
By laws you should have them serviced at no cost.
No questions, good luck.
Mauro.