My two pence worth...
There is no doubt that a SMALL puncture is much easier to fix on a tubeless tyre. Effortless....
And if I were road riding in western countries (where spares and repairs are easy) then I'd go for tubeless all day long..
However, there are CONSIDERABLE drawbacks to tubeless wheels on a motorcycle when over-landing.
Cast rims are far more fragile. They have no 'give' and 'flex' that you get in a spoked rim. Those spokes are a latices of shock absorbers. They don't help with off-roading at all. More weight and harsher ride... This can lead to cracks..
If you crack or break a tubeless wheel you are well and truly stuck. If you're lucky you will find someone who can TIG weld your wheel whilst keeping the correct profile and bead in place. Good luck with that though. It's a specialist job.
Snap a spoke or ding your wheel and unless you're REALLY unlucky, you can keep on rolling.
If you split a tyre on a tubeless wheel you are also screwed. You aren't repairing that one. No amount of slime and wedges are going to help you. I put a 2" gash in my rear tyre in Ethiopia. With a tube, I was able to ride another 60 miles to a town where I patched the tyre and carried on another 200 miles before I could replace it. If I did that with a tubeless tyre, Id probably still be on that remote village road now or hundreds of pounds worse off trying to get a tyre shipped in.
Availability of tyres are DRAMATICALLY increased with tubes as well. You can almost run anything... This is also a huge factor on a long trip.
So yeah, fixing punctures in tubes is a pain in the arse. But at least I CAN fix it and get moving again.
And all this "BMW spoked wheels are great" is cack. Yes you can fix a small puncture like normal tubeless but those tyres are VERY difficult to change if you have to. You see 'GS Adventure' Riders with spare tyres that they intend to use as spares if they gash theur tyres...
Even with the big professional tyre machines at work, it's a struggle... They can take 120 PSI to re-seat too. Even with plenty of tyre soap.... I wouldn't even bother to try and change one by hand. Fools errand unless I was absolutely forced to try.
Another tip... If you're a GS rider, DO NOT run RDC pressure sensors. They are the flimsiest things in the world. They snap off just by looking at them and make tyre changing even more difficult. There is a special way to change tyres with them on a machine so you don't destroy them. Someone with no experience of them will probably tear them off on a tyre machine..
I've lost count of the amount of bikes that end up at our place on recovery trucks after the poor owner snapped off the aluminium valve stem with very little force. You can't repair them and you need to re-valve the wheel. Try that on the side of the motorway...
All so you can see your tyre pressures on your dash board....