Your best bet would be to check which models are supported by Valetudo, which is a local-only firmware replacement: https://valetudo.cloud/ and https://github.com/Hypfer/Valetudo
plus it can void your warranty
I wouldn't consider it a hack. It's an alternative way to run your vacuum, with yes potentially less features if the OEM makes a lot of future updates, but Valetudo also comes with their own set of updates.
[1] https://valetudo.cloud/pages/usage/firmware-updates.html
Unless you happen to live in a jurisdiction that care more about users than companies, like the EU. The manufacturer would have to prove that the new custom firmware is actually the cause of the damage, otherwise they need to fulfill the warranty guarantee regardless of what firmware you run.
You're thinking about it the wrong way around. The manufacturer has to prove that the custom firmware is the reason it broke, you don't have to prove anything. Username not accurate.