Out of stock parts & restock frequency

Looks like Segway US is having a really hard time keeping parts in stock, I assume this is because of global supply chain issues and/or the Trump tariffs causing import problems.

I've been trying to get an external battery since May and it's been out of stock with no signs of when or if it will be coming back in stock. This is extremely frustrating because I really need the extended range the battery can provide.

And now tonight I just discovered the tires are out of stock, right when I was about to order one to keep on hand as a spare so now if I blow a tire it's back to driving everywhere for a while.

Anyone have any past experience with this and might have an idea how often stuff gets restocked and how quickly I should move when something's back in stock?

Thanks