Clearly we can use reason to learn things about the inaccuracies of our sensory perception.
By taking measurements from machines, who are devoid of such flaws.
> I totally agree that it is our duty to identify and account for our biases and inaccuracies, but I don’t think we could ever reach any meaningful certainty about the topic.
What in the world? That's literally what science has been attempting to do for over 1000 years. With varying degrees of success, true, but it's the best way we have so far to be able to approximate 'reality' without relying on our senses.
Re:machines; machines might be better engineered and tested, but they're never perfect - they could be broken, or (much more commonly) they could be designed to measure the wrong thing, in other words using their measurements to justify invalid conclusions. That's what the writing above is getting at and I'm mangling it a bit, but I hope you see my perspective on why I would never say I'm "100%" certain that any scientific fact is true.
Kinda. We still need to know how the machine works, which of course involves making observations of the machine which are themselves error-prone.