I must have missed this one. We didn't come back from our last trip until the 13th. Did you ever gen an answer from Atwood? I'm curious to know what they had to say.
NB, I don't think it's abnormal. Furnace behavior is different for a hybrid than a fully enclosed trailer because of the rapid heat loss through the bunk ends. So it's going to kick in more often in a hybrid. However, I can also tell you that our current Atwood Hydroflame behaves differently than our old pre-Atwood acquisition Hydroflame did.
Our old Kiwi, with the pre-acquisition Hydro-flame, that also did not have ducted heat, would run for long periods and when the temps were really low, like upper 20s, pretty much only shut off for a few minutes and turned back on. But in general it ran for fairly long periods and didn't turn on again unless it really needed to. Our old '93 PUP behaved the same way.
Our current X20E's Atwood furnace will run for a long period and get the trailer warm, then it will run in short bursts similar to what you are describing. Oddly enough it can also go for very long periods without kicking in. So far with this trailer, the coldest we've camped in is upper 30s. But the first season we had this trailer, the furnace didn't behave the same our old ones did.
2013 Jayco Jayfeather X20 E, 2008 GMC Sierra 1500 Crew Cab Z71 SLE