Soil pipe through epdm roof

I'm going be fitting an epdm to a new flat roof my only issue is that I have a soil pipe going up through it which is secured to the wall with the usual brackets so approx 30mm from wall.
I found lots videos online of how to fit the rubber shrouds but they all show the pipes conveniently in the centre of their test roof making it nice easy to seal and make good.
However with my pipe being so close to wall it makes things a bit more interesting.
Has anyone got any tips or information that will help?
Tia kris

There is no quick fix, it can be made watertight but will always be a weak point.
I diverted mine out of the flat roof into a new stack and ic.

There is a liquid rubber compound you can get that will fill any gap once it has set, unfortunately I can't remember the name. This looks similar https://www.roofingsuperstore.co.uk/product/ecoproof-liquid-rubber-mastic-5-litres.html .