It turns out that the STM32 micro-controllers I bought a few weeks ago (in order to replace the ones on “Blue pill” boards that can’t run firmware built for the STM32F103C8T6 micro-controller) are, in fact, re-branded CS32F103CBT6 micro-controllers.

The funny thing is that my ST-LINK v2 programmer/debugger clone uses a genuine CKS32 micro-controller (without re-branding):

Given the fact re-branded CKS32F103CBT6 micro-controllers run the DC2N5-LC firmware without issues, and have twice the flash memory compared to the STM32F103C8T6 micro-controller originally used in “Blue pill” modules, I would have been quite happy if I were sold “Blue pills” with the CKS32F103CBT6 micro-controller, even without re-branding!
If I can source a few more CKS32F103CBT6 micro-controllers, I will keep going with replacing the micro-controller of unsuitable “Blue pill” boards and enjoy 128kB of flash memory, which might allow me to include a JPEG decompressor in the DC2N5-LC firmware too. Such decompressor is already part of the DC2N5 firmware that runs on NXP micro-controllers.
Unfortunately, such “upgrade” will not be available to end users as I don’t feel it’s ethically correct to provide them with “Blue pills” whose micro-controller has been replaced by myself manually.
It might be the case that I end up being able to reliably source “Blue pills” with genuine CKS32F103CBT6 micro-controllers (perhaps from AliExpress), but I doubt there would be enough demand for new DC2N5-LC units to distribute a variant with 128 kB of flash memory.
Stay tuned!