With the V1.5, the most you can expect to drain from my frame is fart dust.
The headrest bolts to the seat pan and the brake cable is routed outside the frame tube.
The only way into the frame is through the head tube... I think.
In other words, my sweat just rolls off not in!
Remember, the designer of the newfangled hydroformed main tube on your bike, Mr. Tohurst, was very reluctant to
even consider drilling holes into the tubing, so inverting to drain fluids is probably the best way to go.