With a slight redesign of the SPI-firmware and the accompanying command-line-interface, I'm proud to present a record high (for me at least) frame-rate for the TCD1304 of theoretically 125 Hz.
I'll be conservative and state that 100 Hz is possible. Because of x-mas I'm away from my scope, so a proper speed-test will have to wait.
The very short version of the story is that wiringpi has been replaced in favour of pigpio, and that SPI-communication is triggered by monitoring the logic state of one of the nucleos GPIOs.
Oh and you can collect 65535 integrations in one go.
or look in the source code.
Downloads are available at https://tcd1304.wordpress.com
The UART-firmware is still crawling away at a pace of just above 1 Hz, but with lots more convenience.