Yep, that's exactly my impression as well - I'm not convinced that PID is the optimal approach in the roaster control case, especially if you don't have bean mass temp. However, this is a new problem domain for me so take that comment (and all the ones that follow for that matter) with a grain of salt.
I've grappled with profile control and my view on it has gone through several iterations since I started the project... at first, I thought I'd like PID control so I could create profiles based on fixed length temperature-based segments (i.e., 3 mins at 300, followed by 2 mins at 320, etc), the approach taken by the hottop p. But this approach doesn't work very well if: (1) you don't have the bean dialed in yet; and/or (2) you don't have bean mass temp (which I don't). Ideally, you'd like to base profile segments on internal bean temp rather than environment temp. Without bean mass temp, though, you're left with manipulating env temp based on approximate roast stage, fully aware that env temp <> bean temp and the two values diverge more and more as the roast progresses.
Which brought me to iteration #2: profile segments that are based on percent of full heat application, ala hottop b. In this scheme, maybe for bean "a" you start off with a 4 minute segment at 100%, followed by a 3 minute segment at 70%, etc, and maybe when c1 gets rolling, you reduce to 20% or something, and so on. This is somewhat like the behmor's built-in profiles but with fixed length segments, rather than the existing difficult-to-work-with relative length segments. Or maybe there's a combination of temp-based segments and percent-based segments.
Regardless, you're really just trying to indirectly achieve the same goal in both approaches: control over the rate of env temp change (remember, we don't have bean mass temp here). Enter iteration #3: this will likely involve using the percent based logic that's already in place to control segments that are based on deg/min rate since that's how I find myself using the percent-based control right now anyway.