Currently I tried STM32Programmer_CLI and ST-LINK_CLI, both more than 100 times slower than StmStudio – StLink – SWD – MCU. This solution can only work up to 4Hz with 1 mcu and less with >1 mcu. StmStudio can run at least 250Hz with more exchanged data.

I need to run up to 20 mcu’s simultaneously (6 is minimum), at least one must exchange data faster than 10Hz, prefer >50Hz, the rest can run 1Hz or sub 1Hz.
Must be able to be addressed by StLink serialnumber.

Mcu firmware is locked so far.
Mcu Hardware (circuit/PCB) is locked, so stuck with SWD.

Would another interface improve interface speed, e.g. Segger J-Link?

Any advice?