Oh, yea, I get the safety angle, but that work has already been done.
If I'm replacing a battery in something like thsas long as I use the same tech, where's the concern?
If the factory battery has built-in BMS, then I should use the same, that's about the only concern I'd have. And if it's NiMH, well, even less of a concern.
And for this use-case, I wouldn't be cheap on my replacements, like I am for stuff that's low risk (like a flashlight that lives in a metal cabinet outside - if that lithium does a runaway, there's little risk).