I did note that increased production doesn't seem to be an outcome, but the early blight problem is the most annoying. Many seemingly lovely heirlooms will give me one or two fruits and then die. If they live longer, they'll give me more fruit- that's actually the idea I had.
These links look to have the information I really needed- the nuts and bolts of the procedure. Thanks so much!
Good Growing to you!

Problem with EB is that the spores are in the air, are airborne. When conditions are right it will develop on the plants whether they are grafted or not. Resistance to the soil viral diseases is improved by grafting and the reason it was developed. But the common airborne tomato diseases sadly don't care as long as it is a tomato plant.

Regular use of fungicides from the day of plant out so that the leaves are protected from the airborne spores seems to have the most benefits when it comes to EB. So try a comparison study and see which approach works best for you.

Dave

I found that the two most important things for success are grafting clips and maintaining high humidity after grafting. But my success rate is still only about 50%.

Thank you, Dave! I didn't realize this about early blight! I'll do the fungicides, definitely. I had jumped to the conclusion it was soilbourne.
I'd considered using tiny coffee stirrer straws instead of clips. I'll order the clips, then.

Thanks to both of you.

perL

I will try this sometime, just for fun.
The technique is very simple but doing it and taking care until the joint is fused is another thin. Obviously with high humidity comes higher infection possibility. So how do you disinfect the cuts and the environment?

Seysonn