Trying to set up a Howa Mini in 6.5 Grendel for a slight built 8 year old. Their 12.5 LOP would be helpful and could be adjusted out as he grows...

Any real world experience with this stock?

I had one and it was too short to my liking. For what you want- should be perfect.

I have one. I like it but think its more of a bench gun stock. Mine is on a 6.5-06 Argentine Mauser action with a 26" Schillin light varmint barrel. The stock is completely adjustable

He will shooting from a rest in my Redneck Blind, that, and a bench to get used to the gun and practice, that would not be a problem.

I bought one for my Ruger American Predator. I could not be happier. They included glass bedding compound. This was my first bedding job, and it worked great.

Got around to measuring the boy, he needs about a 8.5" LOP, Not sure they are any off the shelf units that short. Considering a LSS Gen2 Pistol Chassis to replace the current plastic stock. Could one cut down a buffer tube and fit a minimal stock to get the needed length that way?

for the cost of the AT-ONE you could buy a few take-offs and fit them to him every couple years. Cut ad thin pad, next year or as needed ad thick pad, next year ad spacer, the next time he needs more length fit the second take-off and so on. I have a 22 that my dad cut off for me when I was 7 that has had a number of blocks added to the stock.