Interfacing STM32 processor to Quectel modem without linux.. solutions?

we would like to improve an old device based on STM32 controller, increasing data transfer speed. We cannot use rewrite the entire fw of our application so we cannot interfacing to the modem using its driver. As a solution we thought to use QuecOpen (writing a task inside quectel module and interfacing with it via modem UART) but we are not allowed to buy less than 10000pcs, that is over our requirements…
Someone can suggest some other available solutions? I read that QuecPython allows some modem customization…is this concept similar to QuecOpen? In that case do you know if there is also for QuecPython a minimun pcs number to buy modules?
Thanks in advance.
Best regards,

If you have UART connection and can write code for the STM32 to talk to the Modem why not just use AT commands.
There should be no need to write a custom protocol using python on the module itself.

Just have a look at the AT+QHTTP* family of commands.

Although in the end your transfer speed will be limited by the UART speed I guess.

Hi Abaut,
I wrote UART referring to the current firmware but the right word is SERIAL: we will use spi/usb serial.
Moreover, because the STM32 is quite busy now, we want to manage an upload queue inside the smart module, using threads and mass memory to store temp files…

Quectel has told us that quecPython modules have no limitation in the number of pcs to buy like quecOpen ones, so the problem is solved.