I've kept an eye on this for a while as well.
For those who don't know, DeLorme dropped their support years ago. There have been calls for both ExpertGPS and TopoFusion to pick it up, but despite ham radio returning to positive growth, no mainstream mapping program has picked it up.
I use APRSdroid in town and rural trails, but when I get further out I have Kenwoods; a vehicle d710 and handheld TH-D7A(G)