Anything high acid - like fruit - can be canned without sugar at all. The sweetener of choice can be added when the jar is opened. Mostly sugar is added for the taste - cooking fruit makes it taste less sweet. That's why I went to freezing fruit - it tastes a lot more like fresh when it's thawed.

With the pickle recipes that call for sugar, I suspect it's to offset the vinegar taste. But since it's not a good idea to lower the vinegar a little bit of Splenda might work. For recipes that don't rely on the volume of sugar, liquid sucralose would probably work just as well, as that's the main sweetener of Splenda. Some small-batch experimenting might be needed.

I mostly can meat now, tho I do make regular jams & jellies for gifting.

As for tested recipes - the reason there aren't a lot of new sugar-free recipes is that testing costs a lot of money. The USDA is more apt to test for safety rather than taste.

By the way - I'm a long-time volunteer with Extension, so I have all the books. I don't always know the answers, but I know where to look them up.