For what it's worth......
I watched a very good caster throw the whole 90' of fly line, and a little backing, on my 9' 2wt. Getting 80' casts on a 3wt can be done, but even with a shooting head, you have to be dialed in. Add an unfavorable wind, wading deep, and you might need to call Steve Rajeff to make that cast. 80' is not "easy" on a 5wt.
Water hauling a perfectly match shooting head setup, you should be able to make long(ish) casts with your 3wt. You may need to buy more than one head to find what works for you. Using a water haul will help in wind, and will help with any technique issues. It WILL load the rod deeper, so be aware and bring a backup rod. Sage has a wonderful warranty dept. Going shorter than 30' on the shooting head is ok, if it makes it easier for you to manage. It may not cast as far, but struggling with a too long shooting head won't cast far either. Obviously, you'll need to practice/experiment.....and have someplace to do it. Park pond?
OR
I could loan you a light float tube. I think you and your So. African friend might enjoy it more that chucking and ducking for Goldens.
briansII