Perhaps I'm projecting a little, but: please don't feel like you're stuck there. It's an illusion more often than not.
Of all the hills I am willing to die on, getting another phone isn’t one. Especially if they provide a credit for your cell phone.
https://www.teamblind.com/post/Amazon-Cell-Phone-Reimburseme...
I personally just bought the cheapest $60-80 Android phone from a random Amazon seller.
I don't think the German approach is always the best.
So I call private contacts from private SIM, business contacts from business SIM. I have Apps separated into business and private and the respective profiles are in place. Business partition (so to speak) is managed by employer. Private partition is MDMed by myself.
So I have both worlds - in one device. If my employer decides to delete the business partition. I have exactly no problem with that (we tested it and it worked like a charm - private data wasn't affected. We also tested access to private data being nil).