I carefully follow Loggy's composting guidelines, except for burying relatives in the garden. Having battled Fusarium for decades, I have read most of the literature on Fusarium and other nasty fungi, that are taking advantage of climate change very rapidly. You are absolutely right about diseased material in the garden or compost pile. I have black trash bag that get anything even questionable out of the garden.
Once established in the soil fungi are hard, read impossible to remove, though you can help the soil regain a balanced biome.
Rotating crops helps, but in a limited space of 7 4x8' raised beds your opportunities are limited, to not growing the same thing in the same place two years in a row.
One year I was so desperate, from dwindling basil frozen in olive oil, that I grew my basil hydroponically in 5 gallon white buckets in the driveway. attracting some neighbors attention as to what crop was growing! They pretty much watch my projects anyway!
I turn garden hygiene up to 11 in the fall cleanup and again with garden opening in spring. I dont use pesticides, insecticides, or fungicides, but I do use a scorched earth policy in fall and spring.
Using a big propane weed torch, also from harbor freight, after plants are gone in fall, I flamethrower the beds to remove or sterilize any remaining spores, weed seeds, superficial nematodes, etc and then add a couple of inches of shredded, by lawnmower, maple leaves, readily available! In spring I lightly turn in the composed leaves, or rake back those that are still mulch, and then give the beds another smoking hot treatment, that also take out any creeping weeds that have started growing all over. Rake lightly and let it sit a week or so until the new weed seeds have sprouted, and give them a more gentle flaming. It very satisfying and once again attract neighbors interest, as there is a bit of flame roar.
Its also the best thing ever for those violent weeds that set seed early, and explode them 20 ft in all directions when you touch or try to weed them. Torch them and they are instantly sterilized in place. Also helps with dandy lions in the lawn by nuking puffballs, and now in spring when my lawn is relatively low in dandy lions, the neighbors actually invite me over to their lawns with my lawn dragon.
Many here are trying to go with more diverse lawn without herbicides etc, and fire is ecologically a good solution, returning element to the soil!