To differenciate...
The hot-wire kit allows the required B+ or positive battery voltage to run directly from the battery, through a relay, to the ignition module, bypassing the computer and the 10s of feet of wiring which causes voltage drop. It is an in-line adapter.
The wiring adapter is actually what takes the wiring layout from the 84/85 and lets you plug directly into the 86/87 coil without having to cut and solder as I did. It is also an inline adapter.
When upgrading, the latter is necessary, while the former is optional.