The place I work decided that the iMac Pro was a no buy (much like a couple of models of Mac mini) because so little of it can be serviced locally and the RAM is not upgradable.
We have actually started buying Intel NUCs for our student labs instead of Macs. Adobe and Office work on both.
Serviceability of an iMac in a short deadline environment that is running close to 24/7 with sustained graphic and 8K renders / conversions. It's just not the right tool for the job. If I worked on single track edit with long deadline client work, like at an agency, I think it would be fine for most basic media stuff.
I'm fairly positive the iMac Pro would melt though. Even if it didn't melt at first, the load it lived under would greatly reduce the lifespan of the machine.
eGPU isn't an option. Nvidia if you're working with RAW becomes pretty critical and the support for that was greatly reduced with Mojave. RTX cards have been a gamechanger for most of the work we do.
Also, why are you refusing to look at the iMac Pro? Best machine I ever had.