Actually I own the UMC202HD and while it performs ok with StereoTool, I would really recommend you try another and way cheaper solution with an ALC4042 DAC, to be found in several USB-3.5 mm adapters. You can get them for like € 10 to € 15 or so.
The one I got (
https://www.onlinekabelshop.nl/nedis-us ... 0-15-meter) totally outperforms the UHD202HD in terms of S/N ratio and phase error. Looking on an analyzer, the UHD202HD shows some really ugly spurious signals and increased noise floor above 100 kHz, which you don't want to bother your FM transmission with, should your modulator allow so ...
this economic solution is very interesting, could you confirm if it also acts as a capture device (line/mic input)? I see that it has a 4 pole jack (mic input)