I have an SIAECOSYS and an other EM-50 in 2 absolutely identical bikes, while the SIAECOSYS is like an underpowered, heavy truck, while the other one goes like a rocket.
You have a Siaecosys Votol EM-50 and a non-Siaecosys Votol EM-50? I think there is also Lande Votol and maybe a few others selling NOS or clones.
My Votol EM-30s has SW 2.33 and each speed has adjustable peak torque (% of peak current).
But this is different from the starting torque many are missing. The absolute zero rpm torque. Some of it might be from the motor design itself.
The zero rpm torque is needed when going over a very abrupt speed bump, or in my case its when i nose up to the curb of the sidewalk and then give it some throttle to climb up.
My old ebike was 350watt motor, 600 watt controller, 14” diameter tires, 48v battery but it would easily climb the curb from zero.
My new ebike has 500w motor, 1200 watt controller (original), 15” diameter tires, 60v battery but often struggled climbing the curb. The new ebike is slightly bigger and heavier but the extra power should have been able to climb the curb.
So I bought the Votol EM-30 and it didn’t really fix the torque problem which was really because the lead acid batteries were already weak and the voltage sag made the controller cut off and on.
Replacing the batteries helped but because i have my speeds:
LOW 60 50
MID 80 75
HIGH 100 100
It climbs the curb best in high but thats also trying to go too fast once it climbs up.
Maybe I’ll try:
LOW 10 100
MID 80 75
HIGH 100 100
And that would make my speed 1 my “Rockcrawler” gear and 2 would be residential and 3 would be county road cruise.
If I understand what you are saying the votol sold by Siaecosys are hard coded with torque limits so nothing you can do except use sport mode.
You have some controllers with the crappy SW version but i bet there is still an application they can be used in. Probably in a very light, low speed, high torque vehicle with a 72v lithium ion battery for high torque and low weight.
Maybe someday these will be popular enough that someone will make new ROM for them and offer a ROM kitchen like the XDA guys did for the old HTC smartphones.