If you wanted to add a bar to your Flow, I would recommend the Turbo Bar as it is the closest thing to an actual depowerable kite there is - as far as
fixed bridled kites go. The Turbo Bar can be used on your Flow - and basically every other fixed bridle kite on the market. You don't need to use a
harness with it but it does come with a chicken loop so you can hook in to a harness should you decide to do so.
Fixed bridle kites are totally different than true Depowerable kites. The bar setup on the Access is going to be totally different than that of the
Flow (turbo). Depowerable kites are not nearly as efficient as fixed bridle kites, which is why they start out at 4 meter and go up from there. A
"general" rule of thumb is that a Depowerable kite will have about the same power output as a fixed bridle kite half its size. Actual power output
will vary between models so use this formula loosely.
The advantage you get with a Depowerable foil is that it will cover the same wind range as two or even three fixed bridle foils. So you can get one
Depowerable to replace 2 or 3 kites in your current quiver. This means that you can ride longer without having to change sizes.
For jumping and big air (as you mentioned in your post), Depowerable kites are king and give you the most lift and control as well as the best hang
time over any fixed bridle kite. Not saying that all you have to do is purchase a Depowerable kite and you will be flying like Chasta, it does take a
ton of skill and experience to master air time, but a Depowerable kite will let you boost when you want to in normal riding winds without having to
ride totally overpowered and jump with a "hail mary" style.
The Ozone Access XT is an awesome kite, and Ozone is arguably the best land boarding kite manufacturer on the market - they practically made snow
kiting what it is today. If you are serious about big air then the Frenzy or even the Manta may be a better choice for you as those models have more
lift and performance over the Access XT model.
Hope that helps.