I believe the max travel setting is a relative one, meaning max-travel-from-the-start-position, controlling both in or out directions.
So, if the focuser is positioned at 20000 at the start of auto-focus, and maxTravel is set at 1000, then the auto-focus algorithm is allowed to move the focuser between 19000 and 21000.
There are probably other min and max movement parameters in the Indi control panel for your focuser that control the minimum and maximum absolute position.
Thanks. The focuser is going to be (I haven't built it yet) a relative one, just an INDI driver, interface board, and a stepper motor. I know where focus position is on the linear scale, so I can get it close and have a reasonable number for the autofocus limit of travel. But I have to run the focuser all the way in to store the scope, and I don't want to crash into the mechanical stops. Ideally I'd love to say "just go park it" with one button press and have it run inwards till it was just off the stop, of course, and say "run out to about focused in one go" too. I guess I can just use the INDI control panel for that, so long as I can figure out the correct numbers.