Best advice I would have, is to remove the mountune adapter to see if there is any improvement. Also, there is an adjustment procedure I have read about, but haven't tried that may help, but am not sure how it's done.
I do
not have the Boomba handle on the car now, just the Mountune adapter plate.
I was planning to get the Boomba handle in the spring to help reduce the throw to the max, but some on here are saying it gets way too 'notchy', and is actually very hard to get into the 'down pattern' gears (especially 4th), when used in conjuction with the (more percentage reduction in throw) Mountune plate vs. the Boomba plate.
That adapter plate was such a pain (for ME at least) to get on the car, that there is
NO WAY IN HELL that I am EVER going to take it off to switch it out for something else.
In fact, IF I had some RED Loctite on hand, I would have used that to permanently secure the allen bolt (OR welded it it in there, if possible!), instead of the supplied blue, removable Loctite!!!!
Right now, it IS smooth (even smoother than factory!), and feels great, except for just being a tiny bit too long a throw for my liking, but after hearing about the problems with the Mountune plate/Boomba handle combo, I will just live with it as is.