Front end vibration

[MNnoMore]

I have a 2014 Dutch Star 4018 with a front end vibration that is driving me a little bit crazy. I'll try to describe it as best that I can and what has been done so far. It's a rhythmic vibration that cycles over and over. Each cycle is about 7 seconds long consisting of about 6 seconds of a low pitched vibration that occilates up and down in intensity, with multiple occilations per cycle. The occilations start mild, grow stronger and the mild again. Finally followed by 1 second of no vibration. It then repeats the 7 second cycle all over again. It starts at 45 mph, gets worse from 55-65, and goes away at 70mph. I had the front wheels balanced (glass beads), no improvement. I actually thought it made it worse. The tire guy thought there was inside tire wear on both and I should get alignment checked. Alignment was found to be toed out about .45 inches total. Aligned to zero toe, but it still vibrates. They felt front right wheel didn't spin as freely as it should so suggested taking it to truck mechanic. Truck mechanic said everything up front was spinning as it should. Took it to Freightliner and after 2 hours, 2 test drives, and $500, they confirmed the vibration but found no suspension or front end issues. They did agree front inside of both tires were worn abnormal, likely due to toe out issue. The wear is not terrible, but obvious there is uneven wear, So, about $800 into it and no solution. So finally, my question to you all is, could the abnormal tire wear cause this? Not excited about putting $2k into new tires just to see it helps as tires are 2022's in good shape.