Standard KTM MX models VS. Factory Edition Models ---> Are Factory Edition Models Any More Reliable & Better Assembled?

NO.

FE models are built on the exact same assembly line, by the same factory workers, using the same tooling and process controls as the regular production models.

I'm sure the FE model feels a bit different, but it's because it has different parts on it which could slightly impact something like the feel of the vibration. On the other hand, it could just be that they are stretching for some very minor tangibles to help justify the FEs price tag.

Could be the different clamp setup

Only as good as the employee doing it

Those are also the first 400 built of an all new model. They are almost certainly being watched more closely than the regular 2023 and the later factory editions will be. In the automotive industry there are typically extra quality checks added in when launching a new product. Those sometimes get removed later as experience shows what is or is not a common problem. Frankly since Covid no manufacturer in any industry has maintained the same quality previous to Covid. So a 2019 FE is less likely to have assembly issues than a 2022 any model.

I've had both. I did not see any differences in quality or anything other than the obvious parts differences.

I have a 21 KTM 250SX and got the 22 KTM 250 SX-F FE the other week and was actually wondering this myself just the other day. I went through both bikes when I got them, taking steering stem, wheels, etc. off to check/grease all bearings, bolts, etc. Both my bikes had great quality control (no loose bolts, everything paint marked that was critical to show it had been torqued and after checking confirmed this to be true.

It does feel like the FE as mentioned above because they only make 400/and it is a first run, probably get a little extra scrutiny but everything on both bikes was done and checked correctly. Wiring and all the little details were very well assembled with no pinching or incorrect routing. The FE wheels with DID dirt star rims I will say has had no issues with sprockets being loose after I did 1 round of tightening from the dealer floor. The 21 KTM 250sx I had to do a few times when I first got it with the stock Excel rims. The Factory Edition also had visible grease on all bearings before even taking off the handlebars, wheels.. you could see the different (green/red greases) they used on the different components without having to take it apart. I still went ahead and took everything out.

Other then that though, both bikes have thus far given me zero issues.

From my assembly experience as a manufacturing year, historical data shows that limited edition or low take-rate configurations offer a significantly higher chance for a quality defect. However, building all 400 FEs in a row down the assembly line would mitigate any major concerns. Usually after a few assembly cycles, the operator has the different build processes figured out and little to no impact on quality. But there is such little difference between a KTM 450SX-F base vs. a FE, in terms of work content for the assembly line worker, that there's probably no real concern. It would be different story if the FE models were being built on the 1290R Duke line (mixed model line vs. single model line)

Factory assembly line workers are a different breed. They give zero shits whether they are installing a base model or FE part. To them it's just a part, and as long as it doesn't change their process or work sequence, it has little to no impact on their level of quality. Most want to do a quality job, but they also aren't going to give extra effort just because a limited edition model is rolling through their substation.