So yes there are limitations as to how the test is carried out, as in you cannot select the browser method (Just the same a regular Synthetic test) or the OS. I have attached an image that shows you what you can customize:
You can select the device type, for example, desktop, google pixle, Iphone 6, Black Berry, Etc... The screen orientation, Screen size, and Bandwith ( DSL, WiFi, 3g, 2g, etc..)
My initial answer was comparing a Synthetic on a desktop level to a mobile device level, the options are the same across the board, so there are no limitations or constraints when you compare the two. But they both are limited to the Browser that will execute the test (Chrome) and the OS as not being applicable.
Dynatrace will not add the possibility to run our Browser monitors on Internet Explorer. As you perhaps know MS is also using Chromium as engine for their newest browsers and IE will go to end of life very soon:
Changing the user agent within Chrome might help for some apps which are NOT checking for specific Active X objects or other IE engine related JS option.
What is "mobile channel" for you ? Normally is Msite access + Mobile APP
And what are your use case for using Synthetic ?
Enterprise mobile app are normally "HYbrid" this means business transaction are done on back-end (Msite) and/or calling API Gateway.
In this case 90% of use case for regression/stress test / Availability are covered because OS/Browser are not constraint.
A different story is if you want to use Dynatrace for UX testing browsers, OS, device. In this case you have to use different tools that you can integrate with dynatrace (ex. Selenium, loadrunner) ,, but is a different story.
All other data you need are collected by dynatrace to give you UX/Performance evidence of OS / Browser.
Base on collected data (device, browser, OS, carrier,) you can analyse error, performance issue via USQL and/or interface (one again OS / Browser is not an issue).