I am interested in building an AR-style pistol via stripped lower registered as pistol, or other. I've read everything I can find using the search tool on the forums regarding "assault pistols." As a prior Californian, I am intimately familiar with navigating "assault weapon" laws; but Hawaii's, to me, remain nebulous. In several threads I've read, people here seem to lean on HPD's interpretation of things (for better or worse). In my search, I did not see the below product mentioned anywhere. It, among other solutions, is a popular choice of Californian's for "assault weapon" compliance and I am curious if it meets the letter (not spirit, necessarily) of the law regarding it being un-"detachable." This is the solution I am inclined to lean toward as the idea of pinning or welding the mag to the receiver is unpalatable. Would love anyone else's thoughts on the matter.

Here is the product:
https://www.compmag.net/ar-15-compmag-gen-3/

Here is the demonstration: