I doubt you'll have any leakage by leaving the holes open.

Having said that, I've run drag radials screwed to the rim for over 10 years w/ no problems whatsoever. Ran mid 9s for a long time and made a few blasts into the 8s at around 3900 lbs.
Nobody, including M/T, ever advised me not to run screws w/ radials back in 2006 when I started running them.

CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax