While I agree with all of you in stating that 4895 is a very versatile powder , it's also a popular powder. So that being said when the reloading panic buying sets in, my choice of the lesser popular W748 will stay on the shelves longer.
As an example back in '14 when we were in the height of another gun panic, only oddball niche powders were on the shelves at the LGS's. The only rifle powder I could find was primarily 2000MR and more scarce but available was W748 . I experimented with both, ultimately I found out both are great (but not ideal) substitutes for 223 and .30 cal . So I guess my point is experiment and test with the less popular powders as backups when the panics ensue.