Has anyone tried a common latex caulk to fill in these small cracks? If so, what are results?
Latex type caulk was all we had for sealing a trailer before the new gen caulk became available in the late '60s/'70s era.
From '60 to '65 I worked in a mobilhome/rv factory mostly in frame up and metal exterior/doors/windows stations.
Latex caulk will dry hard and crack in a couple of years. I wouldn't use it on my RV as a sealant.
My '97 5th wheel trailer has most of the OEM lap sealant still left on the roof. I have no idea what brand but its still flexible.
I've used self leveling Dicor on the roof since '05 era when needed and the last time I had to reseal a vertical joint was with Dicor 551 I believe. That was in the '09 era. Its still flexy but I have't tried to remove it.