Butyl sealant (including tape) may never "cure" and that also means it creeps, forever. So you snug down on it, give it a chance to creep a bit, and if you want snug down some more. Just be aware that if you do keep snugging it down, it will keep creeping out from the pressure, so there's a limit to how useful it is to keep tightening down on it.
Ive stopped using Butyl tape on components that can possibly 'move' or 'deflect' - stancheon bases, chainplate through decks, etc. Butyl Rubber does remain 'soft' (remains 'viscous') thus is able to continue to creep. Traditional caulks do cure and over time become an elastic (rebound) that more easily can 'follow' any such deflection.
I still use Butyl tape; but, Im damn careful to totally tighten the components together so that there is a strong mechanical/frictional connection between the solid surfaces/faces, etc. ... assuming that the only advantage characteristic of the Butyl is that will it will more easily 'fill' any irregularity between the non-moving faces of the components Im attempting to 'seal'.
Im having better luck simply using filled elastic (GFlex) epoxy to set my stanchion bases and chainplate through-decks. When in future if I need to remove - wire cable saw, fine toothed FeinTool cabinet blade and/or impact chisel. Ive also raised all the stanchion bases with 1" high FRG 'pedestals' to keep them higher than the flush deck, etc.; pedestals epoxied and gel-coated to the deck. I'll be experimenting with raised 'moats' for the chainplate trough decks. The only place I'll use butyl is non-stressed components such as port lights, etc.
Currently Im putting 10+nMi on my boat per year and my decks get 'water loaded' often, and the Butyl-taped deck components that are repetitively stress affected are just not standing up and sealing against all that 'rigor'. Ive had more time consuming and expensive water leak damage from using Butyl tape than I ever had when using polysulfide, etc. caulks - enough !!!!!!!