Can I ask what you're decompiling with that leaves the internal Amazon "aid" attributes and the internal kindle hrefs intact? You won't be able to "rebuild" that code and get anything reliable.
Unzip the source that's included in my sample and you'll see that my links ALL have hrefs with normal values in them. So links with hrefs are NOT all underlined by default after conversion.
Don't confuse the source code with the internal markup language the Kindle uses. I recommend using the very latest version of Mobi_Unpack
(v0.54) to get a good idea of what's going on inside the MOBI/KF8.
Also note that I didn't really offer an "idea for global suppression." I fully intended my methods to be used piecemeal. Also keep in mind that what I suggested doesn't work at all
on a Kindle Keyboard with the latest firmware update.