So it might as well be a HRL. I use blast mode almost all of the time to deny cover. Well i guess range is different. It's only +3 up to 24" but when you can move 13 with one order, not a big deal.
Well, not really. One, as you've observed, the ranges are different, two, HRL is PS 5 on Hit Mode. Now, I can't pretend I have the slightest idea about what CB did have in mind when they made "always PS 6 LRL for the Firebat", but they did it. And unless we assume they just slap such things randomly, I guess we have to accept they had some reason for it. My personal pet suspicion is - they were chasing some fraction of a point in their cost formula. As in, they made the profile, and didn't liked the way the formula made the final cost round-up, so they decided they need to slap on something to bring the cost up by that 0,0000n-th of a point up. And once they did, all became right in the world...
Your guess is as good as mine. I don't think causing confusion was the point, but I certainly can't prove that...
Also note that PS=6 also applies to the Burkut LRL, so it is definitely a specific CB design choice. I think it is to promote aggressive fire template usage and LRL are pretty deadly.