Is your issue actually in the analog data, that you need to capture it at higher resolution? I’m guessing that the higher the resolution of data, the more latency you might have between captures?
Here’s a post with a python script to hack your analog filtering to reduce sample rate w/o losing as much bandwidth:
Finally, if you can probe the RX pin vs. CANH/L (digital only), you might be able to capture a lot more in one capture w/o needing to split up the sessions, assuming the issue doesn’t need to see the analog data and is a bit-level thing.