I think it is time to clone! I had to do that this spring, when my seedlings I had outside got infected big-time with early blight and septoria.
Luckily, I always grow about two times the number I need, (spares and give aways). I discarded many that were badly infected, but had some varieties that had only one survivor.
Most of these had infected lower leaves, so, I cut off the tops (mostly lightly infected or fine), discarded the heavily infected lower portion, sprayed them with daconil, and replanted in potting soil. I managed to save them all, and now they are as good as the ones I initially grew out that did not get infected.
Thanks, this is very useful. I’m going to try the cutting route. But you did your cloning in the Spring. At this point (early August) can one expect them to develop a sufficient root system to flower and fruit?