I've said at least three times I already have a Garmin which provides X and I don't need another one to do that...
In fairness, I don't think there are many appropriate devices that will only do that one thing.
They pretty much will all have one or more of the other features included.
Would that duplication be a problem?
I think you are probably right, and Garmin created the perfect thing for me with their multisport devices, mainly having a battery life long enough that I can charge it up and go away for the whole week with no issues, or ride around the roads close to home.
I've always used physical maps when away on holiday etc, but they tend to get a bit sweaty and run in your pockets, or it rains etc.
Having recently bought the 920 it would not be a disaster to replicate those metrics but it would at least be superfluous and likely to attract adverse comments from the management.
With a desire for GPX routing rather than just car sat nav type routing, I think the options seem to be
1) an etrex
2) an edge on its own
2) get an edge and a stand-alone run watch cheap and sell the 920.
At least I now have options.