It may depend on when the bike was produced; Originally, I think no Deltech. Then they were putting Deltech on everything. Now they seem to have removed it from all except the Launch D8, the K-one e-bike, and strangely, on lower end 20"ers the Dream D6 (which has a skinny tube frame like a Boardwalk, so Deltech would really help there to prevent break at the hinge welds), and Hit D6 (which appears to have the same aluminum frame as the Mariner, but the Mariner now seems to not have Deltech when it did earlier in the year).

My Launch D8 (just bought) was produced mid-2022. It's on a sticker on one end of the box. Your Unio may be same, as they were priced too high and not moving. Please let use know what your Unio production date is, and if it has Deltech. EDIT: I see you just updated us, I need to read... Nice looking bike! Heckuva deal.

And again, if Dahon's "add-on Deltech" never actually materializes, it's real easy to rig one from high-strength low-stretch line. And if you want screw adjustment like Deltech (original Deltech, now it seems Deltech may be a fixed cable), easy enough to go to a sailboat rigging shop and having them make a short stainless cable with a swaged clevis fitting on one end, and threaded adjustment on the other, just like a shroud from standing rigging on a small sailboat, and just attach that to flexible line loops around the lower head tube and left BB shell (oops, can't do that with motor crank spindle) frame behind motor

Ah, I see your Lectric folder does not have Pinion, that explains it. The Lectrics I have seen locally in the past year with delivery people are their Pinion bikes, and I think that doesn't fold, and a lot heavier than your XP Lite.