Everything good is old, but I can relate to this comment. And I'd certainly consider paying 5 dollars also. But the one thing people rarely touch on is the nature of rescue mk ii. It's the most efficient mid side enhancer ever made, frankly even the mono to stereo effect is using less than anything I've made.
While maybe My knowledge by trying to study Blumlein almost exclusively has improved and I've been gaining new techniques, like methods of denoising, de-essing and noise shaping with mid side rather than things like waveshapers; My efficiency is still like 0.25% (25%) less than Bootsy's.
It's very sobering, and I can say that I've spent weeks where I'd be learning every hour; coming back to code and more efficient math with every waking minute. Even when I'd eat I'd come to realizations that would allow for more efficient mathematics, and yet his rescue mk ii reminded Me that it's not new tech but old tech that he learned from.
Most would move on, but I found it flustering lol; and I've always been amazed by VOS's work.
The reason for the strange harmonic resonance is due to the fact that thrillseeker uses haas that has a HP so there's less effect on the bass. If you were to compare it to most lauridsen haas techniques they'd be very similar.
The delay merely enhances the harmonic distortion, the only way to truly avoid the phenomenon would be to use truly split stereo without any form of interleaving / interlacing / summing / averaging.
It's when that happens that the wave looks damaged that way; the only way to avoid it is to split to dual mono which can be challenging. There's ways that work but by also catering to stereo it becomes more complicated.
I also feel that I should correct you furthermore because it is the lack of harmonic distortion that causes aliasing, especially in the case of the higher registers due to there being less complexity. It's often the result of mid side encoding for instance. Many often forget that there's nothing thicker than true mono, especially because it using double the bandwidth. But the sound is sometimes fuzzy and complex, less to be desired. Simple can sound light and nice.