Why should tubeless tyres be so difficult to fit? Ok they might need a bit of assistance but I don't find the tubeless tyres on my baggage trailer particularly difficult to fit , no more than their tubed equivalents; and I can seat them without needing more pressure than I can get out of a bicycle footpump....
tubeless tyres need to seat more precisely on a bead seat in order to seal. Add a slightly stretchy tyre bead and it is virtually guaranteed that they will be a tighter fit. For some reason the well of a tubeless rim is usually shallower too, which makes the tyres difficult to fit. Note those who proudly announce that 'they fitted brand X tubeless tyres without tyre levers'.....
.... wtf..!!
The standard arrangement (in other applications than bicycles) is that a tubeless tyre is made nice and round, has a stiff bead, relatively stiff sidewalls, and a carefully moulded lip on the bead of the tyre. The net result of these things is that once the tyre is on the rim, it
wants to seal and does so without great difficulty.
Maybe your trailer tyres are more like that than they are like other current bicycle tyres, which are not nice and round, are not accurately sized, don't have stiff beads, don't have much in the way of a nice lip or stiff sidewalls. IME current 'performance oriented' tubeless bicycle tyres don't fit and seal as well as other tubeless tyres. Will they ever? Well, probably not; the stiff sidewalls make for relatively high rolling resistance, which is tolerated in other applications but not so much in bicycles.
To put it in perspective, at ~50mph about 50% of the power that a car uses is expended against rolling resistance. The Crr values of good car tyres are not very good in bicycle terms (about x5 worse in round numbers I think). Car tyres are heavy, too; four car tyres (that support a car of 2000kg all up weight) weigh in the region of 50kg, i.e. 1/40th of the all-up weight of the vehicle is tyres. A typical value for a bicycle is in the region of 1/100th and racing bikes come in nearer 1/200th. You might then take it as read that the experience with other types of tubeless tyre won't translate easily and directly to performance oriented bicycles.
cheers