Unfortunately I can't find a cite for the 4 month. I do have this to give you which is a military medical article to support a 4 month recommendation. CATs in the 5-6 month range were found to suffer a breakage 43% of the time compared to 5% for unweathered, fresh in packaging CAT TQs. Keep in mind that "breakage" for the study not only includes plastic physically breaking, but failures to occlude bloodflow because of excessive turns required...that accounts for straps weathering as well, not just windlasses breaking.
https://tacticalevolutiongroup.com/w...ring-Study.pdf
The article doesn't make the 4 month recommendation specifically, and it simply says to carry them 1) in the wrapper and 2) inside an IFAK, not externally. That's obviously not an acceptable practice for individual users who actually need a TQ. Keep in mind that the 10-year service life on the CAT as mandated by the US Army Surgical Institute is a shelf life and only applicable to it being preserved in the plastic wrap. I think some institutions/management teams get tied up on that and think it means something that it's not.
So, sorry I couldn't give you a "NAR says XYZ" documentation, but hopefully you can write an informed memo using this. For the SOFT-TW TQs that I carry externally, I keep them in covered/flapped pouches that shield the TQ.
ETA: I am the liaison/contact for the company sized paramilitary police element performing force protection at our installation. When I did a drill with them, I inquired about tourniquets.....even these guys "get it", and give up an AK mag pouch or stripper clip pouch (for those carrying SKSs) to carry their American supplied CAT TQ.