I recently started removing the plastic cap on the draw stem of my Protank II. I've heard others have issues but with a ~3mm wick (I use cheese cloth) with no flavor wick I find if I leave the cap on the draw is tight and I have wicking issues when chain
vaping.
With it off the wicking improved greatly and the flavor is better. I use 50/50 PG/VG juice, so if you use higher PG juice it may be different. I've found with most ecig customizations YMMV and it only wastes time to give it a try and see how you like it.