I was wondering whether to ask the same thing. Up on my mountain my soil (what there is of it) is 4. Ph test was the first thing I did and it was 4!!! I have been vegetable growing on raised beds here for a few years now and always use lime because of this problem. I don’t test each year, I just use lime when planting out brassicas, it doesn’t seem to affect anything else in the veg garden.
I always have to use the little collars too, because of the cabbage root fly.