I think two years ago or so I learned that the sim calculates out vs. hit before it calculates type of out. This is important because of many things (i.e. stadium effects, fielding, K's, double plays, etc.).
So, if the affect of the stadium is calculated within the earlier "out vs. hit calculation", instead of being factored-in during the later "type of out calculation", this tells me something that, in real life, would be counter intuitive -- in an extreme hitters park, great defense is more valuable than having a high K rate. In real life, if you don't want your little league ball park to kill you, you would ideally have a bunch of heat throwing arms to keep the ball from being in play, but in hbd, since the out vs. hit calculation is so early, the K only does one thing -- prevents your defense from making a negative play or error. In HBD, having a higher K rate, does not cut down on amount of Homers or other hits. In hbd, the higher the K rate, the less valuable your defense is behind you. So, in hbd, if you already run a good defense, the K rate will only marginally help your pitcher by preventing your good defense from turning an out to a hit or an out to error. This marginal uptick to a pitchers production is difficult to see because the high K rate also, unfortunately, gives the pitcher a downtick in the number of double plays, but not all double plays. The higher K rate only prevents routine double plays from happening. It does not prevent positive play double plays from happening because, if you remember from above, a routine double play comes from an "out", but a +play double play comes from a hit that a great play in the field prevented from becoming a hit and turned ot into two outs. The K is not going to prevent hits/HRs, it is going to prevent your defense from making an error or negative play. This is likely why most folks think that velocity adds zero value. If they're already running a great defense, the value is difficult to see, but if you don't consistently run a great defense out there, the velocity rating can add more value.