Hi Seppo,
I never use anything other than Jpeg for my photography.
I understand all of the arguments regarding RAW being more flexible for post processing, and that TIFF allows lossless editing, etc. etc.
But I have always subscribed to the belief that if I get the exposure right in the camera, (easy to do with fungi as they aren't going to run/fly away

), and that I do all the necessary post camera editing in one or two (maybe three sessions max) edit/saves, then there is no visible deterioration to final image quality.
Other people may disagree with me, but I stand by the quality of my results - and they are plenty good enough for me.
I think if I were considering TIFF, I'd still do the stack in JPEG using the images straight out of the camera as per norm, and then convert the resulting stacked image to TIFF for further editing.
I would imagine that trying to do a stack with 30+ TIFF files could be a very long process.
I don't know if CZM can handle RAW or TIFF files - I've never looked.
Regards,
Mike.