Two of my classmates are a lady who just turned 60, and a lady who has not even graduated high school yet. I am older than two of my instructors! The word "student" does not have an age limit, and does not equate with young and immature as a rule...and being older in no way makes one more correct as a judge of how others need to change. I had nearly half a career before I went to college for journalism and discovered photography classes instead, so I find your assumption of my age to be in need of reconsideration.
...and, I just have to ask; Do you really think I would make such a statement without ever having processed IR film in a plastic vessel? No. I, personally, would not. I have done HIE, EIR, and Efke IR820 in plastic tanks (and the Efke in open trays), not to mention soliciting the experience of those with more experience than myself, and, of course, reading data sheets. You and I feel the same way about blanket statements, etc. I think you have picked an unsuitable target for such criticisms.
The main issue is that the things you are needling me about - non-stated "they" as a source and statement of fact based on information alone, not personal experience - are things that I did not even do. I simply responded to a statement that something "can be" with similarly disclaimed "I was always told that this is just a myth" statement, and named one source that gave me this info, "at any rate". I would not know how to be any MORE non-committal to a statement than that!