What weight does a visiting assistant professorship in a different field carry in tenure track faculty applications?
It would be positive, in my experience, but my department (linguistics) went to extremes to be interdisciplinary. Decades ago,  they were more disciplinary and a question could arise if a candidate held a position in e.g. psychology. But even then, raised questions are usually answered by looking at a candidates CV and publications. In the current climate, I think it would be either neutral or positive, depending on whether there were a need to forge relations between math and philosophy.