@brad.h is the result contingent on the email? Or can they get the result before the email WF is triggered/scheduled? You could perhaps schedule the backend email wf for say a small amount of time in the future - also how are you getting the data for the email? Are there any searches involved or directly from inputs? I’m just thinking out loud but could perhaps this be causing performance issues?
I think everything is less reliable in low cell service so that one is a bit harder to fix
It turns out you can run Trigger Events for new items in database (or when new thing is added). This is the fastest way to send email when new thing is created. It’s roughly 5x faster than scheduling a backend workflow and 6x faster than scheduling workflow on the client side. When you hit bad cell service it gets to be 20x or 50x faster.
When creating the trigger, you need to add only when thing before change is empty and thing now is not empty.