I ran 2 schrader valves on my 68 for almost 2yrs.
The only problem I had was occasionally when I tried to air the bags up in the wee morning hours (in the dark
), I would bend the valve & it wouldn't let me put air in. It didn't happen a lot, but it was inconvenient when it did. I started keeping a few extra valves just in case.
Once I started using my trailer more often, I went ahead & got a comp & tanks to make life easier. I also always kept a 5gal portable air tank as an emergency air source..... but never needed it.