Reading this thread got me wondering more about direction arrows. Sitting next to one of my work benches is a Dunlop K70 rear that was given to me sometime in the 80's that I never fitted. No direction arrow. The Dunlop TT100 I fitted on the front of my son's '53 Speed Twin has direction arrows, one for front and one for rear fitment. The rear tire, made in Thailand, doesn't have any arrows. These were bought and fitted a few years back. Like many I've been spending more time in the garage. I've been recommissioning bikes I built in the late '80s and early '90s with an eye to moving them on. Anyway, the tires on these were bought and fitted in period. Here is what I've observed. The Dunlops K70s do not have arrows. The Avon SM MKII that I replaced on my '66 650 doesn't have a direction arrow. As opposed to the AM26 currently fitted. The Continental Conti Twins only have a direction arrow on the tire that is supposed to be fitted to the rear. The extreme off brands, Sears, Dorcy, etc. do not have arrows. What I can say is the ribbed tires do not have any direction arrows, no surprise really. The "block pattern" type tires are also lacking arrows. Again no real surprise. The tires with a chevron type pattern have direction arrows. What I find anomalous is the TT100 tire. Unlike the chevron pattern tires which appear point up or point down, depending on how you look at them, this appears to be the same either way yet has direction arrows for front or rear fitment. I suspect this has more to do with either manufacturing or driving versus driven rather than water displacement as the pattern looks the same either way.
With regards to tubes being run in tubeless tires. I don't believe that is a problem. The Conti Twins I ran were tubeless fitted with tubes and the AM26 I currently run are tubeless fitted with tubes and I have not noticed anything odd or funny about the handling.