Only 79 RAW files at 20 fps in lossless RAW. I would have anticipated a larger buffer (200) so one would have 10 sec buffer at 20 fps. Must be a limitation in current tech.DP used a slow card, and Ricci here gives a much more informed view, and his findings are in line with the Z9 manual which says 79 uncompressed raws.
Still quite low, but I doubt there'll be much difference between lossless and lossy raw for the types of shooting that need 20fps.
Once you drop to one of the lossy raws (still 14bit) the buffer is virtual endless (500+/1000+).