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Two years later and still not added,

... and no response for over a year.

"Having recently assigned routes is planned. Expecting to have this feature implemented this summer."

-- Any updates on the enhancement requests for (a) Recently assigned routes / preferred routes or (b) routes entered manually by users?

Both (a) and (b) have been industry-standards ... for quite some time: skyvector, Garmin Pilot, 1800wxBrief.com, etc.