ah the plot thickens!!!
Well first at the risk of sounding disrespectful, it sounds as though your previous technician doesn't understand how an oven works in general. So lets for the time being forget that he was even there.
Second- Your owners manual is aways right!!.. any information that I, or anyone else gives you is wrong if the owners manual says its wrong!!.. So in order for you to fully understand your oven read the manual ... and call wolf customer service if you aren't sure about something. Wolf/Sub Zero is awesome for this. Plus if there is a known issue with your product they will tell you and get it fixed.
Third- Preheat your oven as per your owners manual.. on your unit it porbably beeps or somthing similar when it is done pre-heating. 30 minutes is probably a waste of energy, especially on your very well insulated unit. And use the appropriate mode for what you are doing. Start in the mode you want to finish in. This greatly affects which direction the heat will be coming from ie: top, bottom, rear of the oven (in convection). If you are baking in convection bake, pre-heat in convection bake. Other wise you will not get the results you want!
Bake- heat from bottom, intermittent heat from top
Convection- fan on, heat from rear of oven only
Convection bake- fan on, heat from rear of oven, intermittent heat from bottom
Roast mode- intermittent heat from top and bottom
Broil- heat from top only
Convection broil- fan on, heat from top only
Convection roast- fan on, heat from rear, intermittent heat from top
And for your reference your oven thermometer (not the display on the oven) should read between 290 degrees (or so) and 410 degrees (or so) when you set the oven to 350. Your oven is constantly heating and cooling, so when you average 290 and 410 you get 350 degrees (290+410=700/2= 350!). Better ovens may have a tighter range (eg 325/375) but will still average 350. Normally you take 6 readings of hi and low and average to be acurate. Some cheap thermometers are not accurate enough for this test!!
Fourth- Most recipes tell you to use 25 degrees lower temp when on convection (as does the wolf manual). Make sure you are doing this accurately.
Fifth - Since you claim that both ovens are acting up in the exact same way, I am now 99% convinced your old oven was hotter than you thought and probably by a lot (30 -50 degrees is not uncommon). Your double oven is exactly that, two separate ovens bolted together. The only actual parts they share is the power cord and the control display. The computers, heating elements etc are all separate parts. So for both to be broken in the exact same way, barring something like a lightning storm, it is nearly impossible. As, lame as it sounds, you may simply need to get used to your new oven because it acts differently than your old one.
Lastly- according to a wolf manual (not sure if it is for your oven without a model number) only your upper oven has the convection feature, and the convection bake mode is "ideal" for pies. There are tons of great tips in there and complete descriptions of all the modes your oven can do. Basically from a cooks point of view, select the cooking mode by where you want the heat to come from just as you would in any other oven. example: heat from top= broil, etc
If you have more questions, or i didn't answer something clearly feel free to ask again.