Plugging Internal Tubing @ BB Shell???

[Thame Game]

Is it a no-no to plug internal tubes at the BB junction?
I'm just about to fit a TA Specialites bb to my Roberts. Thanks to member CasidyAce I purchased a weather sheath for it from SJS for £3!

To prevent ingress from inside the frame to the bearings, is it advisable to bung up the tubes, or will that create a dreaded moisture trap in the shell?

 

[ishaw]

Water needs to drain somewhere. Bearings are cheap to replace, frames not so much.