Don't know if I can contribute information, or just add to the confusion regarding factory Trick-L-Start installation. Just got back with my new 2552 from the factory last Sunday, and as weather allowed was going over the rig. Was under the hood this afternoon, and found a Trick-L-Start installed in the familiar location behind the coolant reservoir. I did NOT specify this installation, in fact, I had already purchased my own Trick-L-Start that I planned to install as one of my first upgrades to my unit.
In reviewing just this single thread, there doesn't seem to be a lot of consistency to when the factory installs this feature. Looking through the posts, and reviewing ONLY 2552 models, I find the following: JATRAX bought a 2017 model in 11/16 and did NOT have the Trick-L-Start installed; GANDALF42 bought a 2017 in 5/17 and DID find a Trick-L-Start; JDIMITRIADIS got a 2018 model in 5/18 with no Trick-L-Start; and ASHBY bought a 2019 model in 9/18 also with no Trick-L-Start; then I received my 2019 model in 2/19 that DID have a Trick-L-Start. I don't know if there is some other option that triggers Phoenix to install this feature, but I don't think so, since most of my options match others that didn't have it.
I think the Trick-L-Start is a worthwhile addition; it's inexpensive, simple to install, and evidently the factory is willing to "throw it in" by virtue of the fact that they install it at times when not specified, and also have in past shipped one to the buyer after the fact upon a complaint. Until this is verified as a new standard install on all units, it would seem that buyers spec'ing a new unit might want to mention that they'd like one of these units included to be sure they get it factory installed.
As an aside, I now have a Trick-L-Start unit that I bought that I don't need. I'll be glad to donate it to someone who might need one if you will let me know.
Mike