Transports are limited in range by losing hp when they transit hostile wormholes.
It seems like it would be simpler and more intuitive to make them attrition when they are more than X hops out.
That way, you have a clearer 'operating range' for them. And, so long as it isn't under fire, a transport can always make it home.
You could also apply this mechanic to scouts, to limit scout pickets a bit. You can still picket within a few hops of your territory, but to maintain pickets farther out requires paying AIP to clear systems.
Posting this here to see if this seems like a useful mechanic to have around.