Considering the possibility of using any knot for something where it is unsuitable (inside clinch and biner), I have had a closer look at what people tie to their harness. In climbing, the bowline is not recommended, unless secured with a strangle knot to the leg of the bight. The more common knot is a rethreaded figure eight loop, tied directly to the harness. I have also seen the zeppelin loop used, and it seems amply secure, although I do not know about any testing. The knot I was thinking of as a replacement is the Wave loop, presented by Waveling. The knot form is identical to the Carrick Bend, and it might be just as good as any of the other three, but before recommending it I would want to try it for double length drop with a sandbag. The obvious difference compared to the other knots is that it might not jam as the fig 8, thus will be easier to untie after a serious fall, probably even easier than the zeppelin. The wave loop is about as easily tied as a bowline.
Because you don’t want to compromise the strength of the line so much,
and you might want to UNtied the knot sometime.
–dl*
Also, for a halyard, you might want it to get as high as possible, and if you tie a stopper either side, there will be at least some distance between them. Then the snapshackle would not come up as tight to the shiv as if you have something that stops directly on top of the snapshackle. It would perhaps not be much more than about two inches for the knot and the distance between them, but it might be unwanted. There’s hardly any risk of approaching breaking load on a halyard. Too hard tension would compromise the shape of the sail. Regarding untying, the inside clinch, well set, is about as hard to untie as a stopper. A single half hitch is easier to untie, but for a cautious sailor might seem minimalistic.