In the late 1980s, I had to use some scientific instruments that our company rented, they were too expensive for us to buy when we only needed them a few days a year. They had lithium batteries in them. We could ship by Fed Ex because the restriction at that time was about passenger aircraft, not all aircraft. We had a stack of information from Fed that documented how to ship things like that.

I think you can ship by UPS or US Postal Service on ground transport. For example several years ago I bought a big box of butane canisters for camp stoves which can't be shipped on aircraft, but Amazon shipped it to me by ground carrier.

My point is that if you have someone, a bike shop, a motel, you may be able to ship the batteries ahead of time.

I assume an e-bike without battery might still be too heavy for the 50 pound weight limit on some airlines, you might have to use Bike Flights. Or see if Bike Flights has any info on shipping batteries.

A friend of mine has an e-trike with a Bosch motor. I suspect you would want a high end machine that uses Bosch if you want anyone to work on it. A neighbor is a bike mechanic and he tells me that no regular bike shop in town will work on the cheap e-bikes. Even their spokes were so weird they could not replace them with normal spokes.