if you use a dongle you basically half the range in each mode so in eco no dongle would say 100 miles and half that with one.
I can't understand your statement. I have a Haibike Sduro Cross 7.0 (CX-motor) with a Speedbox 2 dongle. The dongle doesn't effect the range. The Intuvia screen doesn't change estimated range whether the dongle is on or off. And of course it shouldn't because the dongles doesn't change the torque in any way, only the 25 km/h speed limit.
I have several trips of 70-75 km on very rugged and hilly forest roads with one Powerpack 500 and still with some km left. (1 LED)
What matters for maximum range is:
1. The mode. On these trips I try to use the Tour-mode as mutch a possible but need both Sport and the Turbo-mode on the steapest hills.
2. Optimal gear shifts. (Many do gear down to late before hills and with to low cadence before and up the hill)
3. Cadence
4. And of course, the power in your legs.(I'm 60 so my power is not what it was)
If your dongle gives you only half of the normal range something must be wrong.
Btw. Speedbox has a new version, Speedbox 2/B which has an bluetooth app that gives you many live data parameters.
https://play.google.com/store/apps/details?id=com.speedbox.app&hl=en
The sad part is that I think the B-version it's very expensive. But the data it shows is very interesting, and many of the parameteres would be nice showing up on Bosch displays on their ebikes in the future.