In
this post, the Developer of the 2box software suggests that the hi-hat will open up in terms of configuration possibilities...
"Next OS will have a separate open and closed calib, so one can adjust this range to ones liking."
...so fingers crossed you'll be able to tune it to your liking.
By the way, when you calibrated your hats, did you loosen the screw, or hold it closed with your foot? ...the latter worked well for me on my Pearl stand, and I don't know if it's what makes the difference but I think the spring's on its way out (it's about 15 years old) so at rest it actually hangs kinda low, but I actually like it like that....maybe you could loosen the compression / tension on the spring a bit, see if that helps?