It's unlikely they do different boostings to the same rubbers. Back when dima was with Donic he still used tenergy, it's likely they were supplied the rubber in mass to the teams. He wasn't sponsored by them so he didn't get any special treatment, and the rubbers sent by mass would be identical.
Yes, he played Tenergy while still being with Donic. However I do think that Dima is perfectly capable of boosting his rubbers the way he wants to (if needed) and doesn't necessarily need other people to do it for him.
It is also an open secret that he used to use Dymax Maximizer (perhaps still uses it...?) and, on a side note, I kind of vividly remember that years ago someone on the german forum posted that he had seen Dima in the Butterfly Store in Moers (before they moved to Krefeld to set up their new european HQ) and when you could actually go inside and test/buy stuff (you can't do that in Krefeld). Dima was apparently selecting
huge chunks of Tenergys according to their weight.
Of course you can do that
to some degree yourself in a store, but we mere mortals likely cannot ask the staff to go get you a couple hundred sheets of Tenergy (or Dignics, MX-P etc.) in order to weight select them, and also back then Dima was officially under contract with a competitor, Donic, even though the german national team was already sponsored by Butterfly.
In any case, they (Butterfly and Dima) knew each other very well already back then - which Dima confirmed when he officially switched to Butterfly. Dima surely got some preferred treatment back then, but probably not the same as the sponsored players such as Timo.