The tablet has no GPS of its own, but I have it receive the signal through an Android phone using com.jillybunch.shareGPS .
It should be important on EPD displays, which are bistable, to update the screen as little as possible. The GPS cursor is updated on the screen every two seconds. I would have it update every 10 or 30 seconds - more frequently is not needed. There is an option, in "tweak GPS settings", to update on either every 1 sec, or "Default", or every 30 sec - but the option does not do anything.
How to limit screen update (and also possibly limit retrieving the GPS data via the bluetooth, for the same reason of preserving the battery charge)?
Of course, I also disable GPS tracking (the "[scroll through] finger" icon).
I am updating a thread on mobileread.com ; the original poster published with title "T68 for DIY E-ink GPS on a motorcycle".