Are these spots an early sign of deficiency?

I’m going to agree with NorCal on this one but be sure to get your runoff ppm/ec and ph. In the past when I’ve ran OF I have had very high ppm and very low ph. I’m talking 3000+ ppm and 5.4ph and this was with an input of 6.5ph. This caused lockout of nutrients which caused deficiencies. At first it would seem like you need nutrients but in reality it’s nutrient lockout and adding more nutrients will just raise the ppm even higher! Since you’re running an autoflower you don’t need nearly as much nutrients as a photoperiod plant would. Honestly autos really don’t even need many veg nutrients at all but benefit from about the same amount of bloom nutrients as a photoperiod plant during flower. I solved this issue while growing an auto strain but doing a flush and raising my input phnwith an organic silica product called Agsil16h. It’s technically potassium silicate and scholarly sourced research has proven that it is the most readily available form of silica for plants compared to any other type of silica. I raised my input ph with this product to around 6.8 and by the next two feedings the runoff numbers were much better. Around 1500ppm and 6.3ph which is optimal for flower. I hope this helps a bit!