Harlan (my dealer) reprogrammed my ECO mode so that it has the same acceleration curve as is standard in SPORT mode. Except for the regen deceleration in ECO I can't tell the difference now. Ask your dealer to reprogram your ECO mode for fast acceleration (equal to SPORT).
You mentioned wanting regen in SPORT mode. There is some already in SPORT mode but I want to go the opposite way and ask Harlan to reprogram SPORT mode for no regen at all. When I'm dirt riding I want to chose between free coasting in SPORT (no regen) and rapid deceleration in ECO (full 25% regen) selected "on the fly" by a "clutch" type lever on my left handlebar. It will require a two pole "micro-switch" operated by the lever. One side will short the ECO mode switch contacts (set in SPORT mode) and the other side will drive the stop light to kick it into 25% regen. This is what I'm working toward.
There is no harm done (I've been told) by switching between SPORT and ECO while riding (no matter what the manual says) except Harlan has warned me that in the logic system there is a register that is totaling the number of times it is switched. After thousands of cycles I will get an "error" indication. I can't figure out why ZERO designed it to tally up the number of ECO/SPORT changes. Makes no sense at all
ZERO, if your reading this please "splain" the register's purpose!
Trikester