Oh, no, I mean I'm able to transition into H&E after HRS 2 and use one of its follow-ups without using up any heat gauge, even when I have zero stocks. After some labbing, I've found that the most consistent timing is mashing out one of H&E's follow-up attacks during the last punch of HRS 2. If it's performed correctly, you transition into H&E without expending any heat gauge, and the follow-up attack comes out automatically, sort of like the input got buffered during HRS 2. But like I said, it feels very inconsistent, which leads me to believe it's a bug, but it's a really strong one if that's the case.
Here's a recording I made to show what I'm talking about:
And here's an example of it in a real match. It happens in the first round of the first match: