Potassium Deficiency?

Hi guys, I've got an outdoor plant that's about 2-3 weeks from harvest. I'm noticing some fan leaves getting damage on the margins, looks like potassium deficiency to me.Temps are averaging 75 daytime, 65 night. It's just the oldest fan leaves taking damage.

Soil is native, lots of clay, amended with a ton of organic matter(fine leaf mould and some N guano,) a 5-10-10 NPK, as well as a triple superphosphate (0-43-0), as per soil test result recommendations. This soil has grown about 150 pounds of tomatoes in other beds this year, among other veggies. I'm now seeing similar issues in my tomatoes.

So I'm not sure if it's a real deficiency, or maybe temps? Or something else? I haven't fed anything beyond the initial amendments, and mostly rely on rain for water. There was no mid season fertilization, as it hadn't appeared necessary. Is this the sign I should have top dressed? Would be good to know for next year.

Looks like potash for me but it's my first outdoor, growing anything, so not sure what to expect. Any help appreciated.

They look good, I'm sure they will make it, I hear, less is best so what ever you do don't over react, Best of luck to ya

Something I failed to mention was that we've had some wicked wind lately. After seeing some photos of wind burn, it looks similar, so I'm hoping that's all it is.

It seems like damage is mostly toward the outside of the plant, from the middle up. So I'm hoping it's wind. But if anyone sees something else please let me know.