I've never owned a BC, drysuit, or set of fins that I didn't modify to some extent, but I've never been one to care much for what the manufacturers think. I usually don't even bother to send in warranty cards, except on computers and regs.
Off the top of my head, I had a Seaquest BC that I added a second cam band to, and then mounted trim weights on the original band. I also found it difficult to open the pockets on that BC while wearing cold-water gloves, so I popped brass grommets in the flaps and tied on big wooden beads I could easily get a grip on.
When I had a Transpac II after that, I again put holes and grommets in the shoulder straps so that I could tie bungie cord loops through them to hold my light while it was clipped off.
I glued a 5th Dimension bellows pocket on to the left thigh of my drysuit. I also punched a hole in the left leg so I could install a P-valve, which has been a great addition.
The Weezle Extreme undergarment I wear with it has a diagonal strip of medium weight synthetic fabric glued across the front to help prevent the lighter weight outer fabric of the suit from getting caught and ripped in the drysuit zipper (again).
My fins all lose their straps before they hit the water, and I put on custom built spring straps.
I removed and discarded the housing my Suunto SK-7 compass came in, and mounted it in an aftermarket DSS bungie wrist mount. I did the same with my Uwatec bottom timer. The Bezel on the SK-7 was replaced with a custom part I made out of thermoplastic.
My BP crotch strap and Jon line as well as all of the stage rigging on my deco cylinders is DIY... no manufacturer involved unless you count me.
I replaced the laces on the Converse All-Stars I wear as drysuit boots with bungie cord.
I've also modified a ton of other stuff, but I don't care to think much harder about what things I've tinkered with over the years. In any case, there's still a good sized pile of DIY modification and building projects I still haven't gotten to, and so far I don't have a single regret.
scarefaceDM:
well to be honest..to add any thing to a BC would be pointless.
That's ridiculous. If you can improve something, go ahead and do it. If you can't, don't.
scarefaceDM:
You exceed manufacture standards for such a modification unless it is to repair something or replace something.
Yes, and as we all know, there's a special layer of Hell reserved for those who exceed manufacture standards. Better to exceed them than to fall short of them, I say.
scarefaceDM:
Plus in the event of an accident..Heaven forbid...all warranty etc would be void becaue YOU tammpered with the proper operation of such gear.
Very scary.
scarefaceDM:
The only thing of value to add would be trim weights which is Optional gear which as mentioned is attached to tank straps. Or sewn in a strategic area on the BC. Say upper head, middle and or lower back area. Maybe a buckle or something of sorts.
Yes... nothing else you can do would be valuable... unless you can think of something that is.
scarefaceDM:
On a flip side...if you sell your rig and you did mods to it..chances are the person may not want them mods and then you may be stuck with it.
That's an excellent reason not to make crappy modifications. I've never had a problem reselling, and have in fact been able to get more than the going "used" rate for some modified gear I resold.