I have discovered thrips on one of my plants and a...

Hey man, sorry to hear about that. Is it def thrips you seen the bugs? Wouldn’t personally advise spraying anything on your girls now. Neem oil would have been great before flower I’m not familiar with vaping it but I wouldnt touch my buds with it now. It looks like you have a K deficiency it’s why your buds could have taken so long to develop the withered looking tips can be K def or lock out. It can look like nutrient burn. For the thrips you can do 2 things, leave them and do a bud wash you can find out how to do this online too much explain here. Or you can get some Amblyseius “defender pests” they hunt and eat thrips. You would also have to cover your soil in either sand or perlite a thick layer so nothing can survive in the soil. Because the last step is could reinvigorate for the rest of flower if you want to that is. You make up a H2O2 (hydrogen peroxide) solution and feed it to your plants, this will kill anything in your soil. This could take 2-3 weeks to sort out if you act fast.