OK, here is the update. The second mechanic seems very knowledgeable and transparent.
He ran a few tests including a vanos test. He said the test couldn't complete on bank 1, just stopped. So the 20% cam adjustment couldn't be completed. He suspects that the vanos on bank 1 is defective. He will charge me 10 hours (100/h) to replace both vanos. I have the option to buy the tools and attempt to do it myself but the timing seems tricky and I am not sure I can do a good job. The vanos tool kit is about $400 shipped. So I would save $600 or more is I resell the tools.
If he takes the valve cover and the upper front covers off and sees that the chain guides are damaged then the cost is 20 hours or so for the whole job. If that's the case he will charge me only for the disassembly portion and I will tow it home and I will change the guides myself. He was very confident that the problem is the vanos and the chain guides are ok but... we will see. Thanks for all the tips. I will update when he takes it apart.