If I was you, I would just wait.
I've sent an email to APEX about my experiences and await their reply.
I've tried both match KKM and Wilson drop ins and while they preformed better than the factory 10:1 twist I've got, neither was anything to brag about.
The S&W and Wilson barrels was also short leade but long enough for all the factory ammo I tested in them.
The KKM was as long as my 1911/2011 barrels and could take 1.170" oal jhp without a hitch.
Many subscribe to a short bullet jump from case to barrel for accuracy.
I put off going with another fitted barrel by others waiting for APEX.
Their barrel is really beautiful.
I may just have a off barrel.
I have a bunch of other APEX stuff in my M&Ps and have been very happy with them.
Their trigger and sear kits, springs sets and RAM systems made my M&Ps like a good 1911, light, short crisp triggers with short trigger returns.
The worst that can happen is I take a finish reamer to it and recut the leade longer.