I've never seen accuracy issues with a conversion kit, but I've never seen one run on a 1:12 barrel.

In my experience, the conversion kits tend to have reliability issues over the course of a weekend. Some run flawlessly, but I'd say 75% have some hiccups. Nothing more frustrating than having a good AQT score ruined by a FTE.

If you decide to buy the conversion kit, I'd suggest putting it through its paces before attending the Appleseed. Throw 500 rounds through it without cleaning and see how it functions.

The 10/22 is a fine choice; though the stock sights are, shall we say, below average.

You never know what kind of accuracy you will get with a 22 conversion. I've read where some 1 in 12 twist didn't do much better than 1 in 9 twist. The biggest problem with 22 AR-15 conversions is fliers. You may have 4 rounds into 3/8" group only to get a flier opening the group to 3/4" or more. Some ammo is just better than others. Personally I think a new CMMG conversion with good mags would have the reliability but your really ought to figure on groups of 1/2" to 2" at 50 yards.

Considering the poor trigger of my brothers out of the box 10/22 and poor fixed sights I bet I could hold my own shooting against him using his 10/22 and me using my 1 in 9 twist 16" AR-15 with conversion kit. I personally just like the way my AR -15 slings up compared to a 10/22. For some reason Agula Super Extra 40 grain HV plated round nose gave me the fewest fliers and best groups out of my 1 in 9 twist barrel 223/5.56 barrels.

Normally if you do encounter problems with filth from shooting 22 rimfire on the range a paper tower, bottle of CLP and a bore snake will have an AR -15 with 22 conversion running good in a couple of minutes.

my 22lr kit w/ 1:12 twist is good... you also have to take into account ammo / bullet weight
ammo can be very finicky...get a few types & see what works best

dedicated uppers are mostly 1:16 twist.

i am about to build a dedicated upper w/ 1:16 barrel

either way w/ AR options... as mentioned above you need to break it in well prior to the match.

i dont own a 10/22, but if you go that route... i have heard tech sights are great on those.

Out of a 1:9 barrel the best I have gotten with my conversion is 4 - 6 MOA which is borderline for shooting rifleman and makes it very hard to diagnose what, if anything, you are doing wrong vs. what the rifle is doing wrong.

I shoot rifleman (220 - 230ish) without any problem with my ironsighted AR and 10/22. Using the conversion makes it a crap shoot on whether I will get enough of the 400 yard points to make it.

I have used the conversion in the past for the first parts of Appleseed then switched to centerfire when we start firing for score. That lets me get some sight alignment and trigger practice without the expense.

ETA - You also CAN NOT dry fire a conversion. You will break firing pins. If you do use a conversion buy some plastic .22lr dummy rounds from Brownells to save the firing pin. They also work great for ball & dummy drills.