Lets go all silly. How about inflating your kite with helium??? lets forget that helium is as expesive as hell and consider the performance advantage. the lighter your kite is the better it performs. therefore a helium pumped kite should have awesome performance.
I wonder if it would float in the air unassisted by the wind?
its easy enough to do the calculations ps lets use hydrogen instead because then
when your kite hindenbergs it can REALLY hindenberg
weight of air at 1 stp is 1.2 grams per liter
weight of hydrogen at 1 stp is .09 grams per liter (half as much as helium)
1.2 - .09 = 1.11 grams of lift per liter
i know my pump has 4 liters and a medium sized kite will take about 35 pumps to losely inflate or 140 liters for about 150 grams or 1/3 of a pound or 0.15 kilos of lift which means not even bothering to correct for pumping up the kite to 8psi, we can already see that
NO WAY will it float.
inflating with hydrogen or helium it doesn't matter, will have no noticeable effect on either lift or performances kites weigh a few pounds and 0.15 kilos just wont be enough to make a difference (actually after you pump it up to 8psi it will be only 0.05 kilos of lift or minuscule two ounces of lift if inflated with hydrogen is which twice as light as helium)
I was thinking the same way as you it would be cool if your kite floated by itself but the calculations soundly disprove that idea. unfortunate.