Butyl oozing is usually due to two reason. Improper installation and a low quality butyl that is prone to cold flow and creep. There are literally hundreds of formulations of butyl tape out there. At last count my US manufacturer makes approx 46 different formulations. Bed-It Tape is their 47th, and we went through many more formulations to get there...

The hatches on our CS-36T were bedded in pre-EPA quality butyl 35 years ago. I only rebedded the bow hatch because we wanted to change the opening directions this was at year 34. It had zero signs of leaking after some 70k nm and 34 years.. They other hatch and genny tracks are still un-rebedded from the factory install and they are still bone dry...