I am "venting" because there shouldn't be inletting problems on a $1200 kit.
I can probably guess which kit maker you're referring to. I'm dealing with pretty much the same thing, with a $1200 kit. Inletting metal to wood and building from a slab is no stranger to me, but for this rifle I figured a reputable kit would be a quicker means to the end, due to current circumstances.
It will be the last kit I buy from them for any reason and I'll go back to scratch building from now on.
My issues weren't over sized mortises, or misaligned parts, or anything like that. It was just very sloppy work on what they did cut.
For example, the trigger mortise was done with I'm guessing a hand held router and it must have caught and slung a small radius cut on each side of the mortise which was big enough I had to make pieces to fill them. Fortunately it doesn't stick out after all the metal has been inletted, but i know it's there.
Another thing was so much wood was removed from the lock mortise I felt I couldn't trust it's strength so I milled it clean and made a piece to snap fit in, epoxied it, and recut the mortise myself.
The barrel channel is straight and clean enough, except for the slivers of wood missing on the top edge where the router bit turned the wrong way to the grain and broke out slivers. I'm hoping those disappear, or at least minimize, when i block plane the top of the stock.
It's just a bunch of little stuff that one by itself I could keep quiet about, but it's accumulated enough that i said never again. I know what work to expect on a kit but I would have been embarrassed to let this stock out the door.
I'll fix it all and it won't show to anyone but me, but they got the last $1200 of mine. I'd rather sink the cash into better parts and wood and come out ahead just doing the work myself.
Edit to add: I understand production through put and using a router is faster, but it's not better. If you MUST use a dang router to meet your bottom line, then for the love of God A'mighty teach your people how to use one.