Most base oils are very benign towards seal elastomers. Ditto VII polymers.
Seal problems usually begin the moment you start adding additives to the oil and it's usually those additives that contain active, 'exposed' nitrogen or sulphur sites that are the most problematic.
The funny thing about oils which are seal aggressive is that almost from the moment you add them to your engine, and start turning the oil over, their aggressiveness drops off. I never really believed that oil compatibility with seals was such a big deal in The Real World but logically, if you were worried, you wouldn't operate to short OCIs.
Seal problems were once the bain of my life because a typical Euro-oil might need to meet ACEA, MB & VW specs. That meant three different sets of seal tests to pass. Each set of tests might compose of upto four different elastomer types and each individual seal test would be rated on say four different parameters (tensile strength, elongation, hardness, volume swell & cracking). Basically it meant you needed maybe 150 passing ticks in 150 boxes BEFORE commencing expensive engine tests and if you got it wrong first time around, you would have to start all over again. Arrrrrgggghhh!!