Currently the superheat spell does not detect the coal in your coal bag, please program this fix, as Rune Ore takes a long time to run and is more efficient to use the spell, also ensure that varrock armor 4 works with the spell too! Thank you
I agree with the Coal Bag because that's how it operates in 07; however, that is not how the Varrock's Armour 4 works in 07. It only applies to furnaces, more specifically the Edge one.
Your first suggestion would be very handy to have in-game, hopefully it'll be looked into and fixed in one of the next upcoming game updates. Going to have to no support your second suggestion, for the reason Savitr has already stated.
Looking at the feedback, and how things operate on OSRS, I am going to add the suggestion for the coal bag + superheating. As for the second suggestion, I don't think that would be a good idea seeing as it doesn't operate this way on OSRS.