90% of dry-suits sold will need some latex seal trimming…so this is normal.
for ankle and wrist seals I trim no more than 1/8” or 3mm of the ends. And then test fit after each cut. If the seal is really tight I make my first cut at 1/8” and slightly scale back the second cut.
You must be more precise with the neck seal so if your close on the comfort don’t trim more the 2mm per cut. Take more frequent thinner cuts with the neck seal…
For trimming all the seals the best method I’ve found is to cut the seals “flat” so your not cutting around the circumference and potential nicking the seal. This is a volume trick I’ve used from fitting seals at trade shows. You need a helper to hold and tension the seal flat so you can make a nice clean cut straight across - the trick is to hold the two layers edge to edge,..you don’ want them to slip. Be careful not to cut your helper with the scissors! (we’ll post a video on this very soon).
I’ve trimmed hundreds of seals this way and so far so good,...a few pics attached.