Hmm, I was really pointing at the fact that once you get past a couple of pieces of user input, all the validation in the world isn't going to save you from the range constraints.
Assuming you want a good faith conversation, then the idea that there's bad math involved seems a bit ludicrous
I believe that the solution here is to make crashes "safe" eg with a supervisor process that should either never crash or be resumed quickly and child processes that handle operations like user inputs.
This together with the fact that the main benefit of range types is on the consumption side (ie knowing that a PositiveInt is not 0) and it is doable to use try-catch or an equivalent operation at creation time
For some reason your reply (which I think is quite good) makes me think of the adage "Be liberal in what you accept, and conservative in what you send" (Postels law).
Speaking as someone that's drunk the Go kool aid - the (general) advice is not to panic when it's a user input problem, only when it's a programmers problem (which I think is a restatement of your post)
Happens with DB constraints all the time, user gets an error and at least his session, if not whole process, crashes. And yes that too is considered bad code that needs fixing.