Is the statement "Claims demand evidence" always true?

[The Grand Nudger]

Yes, and I've read that even sets of macro objects, like say a few quadrillion office chairs, if treated properly, will also do so, though of that I'm pretty dubious.

I'd love an attribution on that.  That other elementary particles, atoms and molecules present themselves as-such has been experimentally demonstrated...but I'm not aware of any experiment to that effect involving office chairs.  Would be interesting to see how they draw the conclusion, at least.  

I don't have a problem with it, because I view truth values in this case context-dependent.

You just said it didn't make sense to you.  I'd call that a problem.  I'm suggesting that you've invented a dubious solution for a non-existent problem.   

I've often argued against science, at least as described by materlialists like you.  But in this case, I'd say that many of the new contexts through which we view our experiences, could only come about through scientific theorization and experimentation.  While duality/ambiguity have been around for thousands of years, science has really given us tools to play with them.

Indeed it has, some of those tools may speak to the things that don't make sense to you. Bohmian mechanics, for example, doesn't require a "truth-in-context" workaround to the issue that vexes you. It has the benefits of predicting everything that the models which -do- see paradox predict, but also of handling things which completely baffle other interpretations. This isn't to say it's without objections (or even remotely true). One common objection is that it's merely the same model, supplied with an ontology....but..given your previous statements, ontology is -precisely- what you seem to be wondering about.