I wouldn’t put any kind of foliage feed on tomatoes due to blight risk. In fact I’ve been reading up on fertiliser type and blight, and apparently high nitrogen feeds are not recommended as they cause a lot of rapid leaf growth, which increases risk of blight. Comfrey feed is supposed to be high nitrogen, although I’m not sure how much it actually contains ( it must depend on the recipe used) and if it is as much as commercial feeds. I’m not going to use it as freely in my toms this year as I did last year.