Wow excellent job indeed on the HA-5002! Thanks for sharing the impression of HA-5002!
Just wondering, why you choose the SOIC-8 type for the HA-5002 and not the DIP-8 ?
The quick answer is, well, HA-5002 doesn't have DIP8 version. It is either SOIC, PLCC or metal can. Even if there was an DIP8 version, the pins out aren't compatible with regular buffer anyway so it still won't fit the E12DIY. SOIC with the special BrownDog adapter is the only way to go.