After receiving some feedback on my other question, I have improved my design.
I am still using a stm32f030k6 to drive a two-digit 7-segment display, but I am using the common-anode HDSM-291C in order to be able to use the STP08DP05 LED sink. Since that IC is specified as being a sink (although source is mentioned in the description?), I concluded that I need high-side transistors to toggle the digits, and since commenters suggested using a MOSFET I chose the dual-channel SQ3989EV.
I am reasonably certain that the STP08DP05 should do the job. It is connected to a set of SPI pins on the MCU, since the protocol (8 bits at a time clocked in through the CLK pin) seems to be compatible with SPI. I've connected the outputs to the cathodes of the display, and as far as I understand I should be able to toggle the brightness of the LEDs by using PWM on the OE pin.
I am far less certain about the transistors. I have tried to research LED drivers and found people using similar setups, but I have little personal experience with transistors. Do I need some kind of current limiting?
I would like to know if any of my assumptions are wrong, if the choice of ICs and transistors is sensible and if I've missed anything else.
Thanks for any help!