It is not just your own risk but also that of other pedestrians, cyclists, and drivers that share the road with you.
"At your own risk" means you bear the risk (legally). If something happens, it is on you, and the manufacturer offloads any liability on you.
That does not imply what the risks are. Life threatening? You are risking other people's lives.
While a reasonable interpretation includes putting the driver at increased /legal/ risk relative to a system where the manufacturer represents it as for sale for autonomous driving, it is unreasonable to infer that this puts the driver at greater risk of being sued, having to sue, or monetary loss. OpenPilot may be better / safer than the competition such that using it lowers your risk of accident, monetary loss, etc. even including any purported loss of the ability to pass the buck to the manufacturer.
[1] https://www.reuters.com/article/selfdriving-safety/comma-ai-...