Sig makes good 1/2A fuels(but I have yet to investigate), glowplugboy does too from what I have heard. I always add some castorto the fuel I buy from the LHS because its not enough castor for 1/2A, evenglowplugboy fuel is at the 17% castor mark,I prefer at least 20% castor and normally add to my fuels to bring thom up to 25% total lube from the 17% that the norvels require si my engines live long lives.
I have used that hobbico 1/2A fuel years ago, but I spiked it with some castor just because it does not specify how much of the lube is castor oil and at 18%lube it is a little lower than I prefer. So if you add about 1/2-3/4 oz castorto that hobbico 8oz bottle you should be well lubed for a cox to live a long life. Using it straight may shorten engine life some,but there have been fuel discussions before regarding this matter too. I prefer to get my molneys worth from my engines as much as possible and like the peace of mind that I tried to do so.
Your preferences are up to you, it should be ok as is to run hobbico 1/2A,fuel but the old cox fuel had more lube than that.
I try to get as many years as possible out of my engines.