A Connecting Wall off the beaten track!

This is an extended hybrid connect-wall puzzle which fuses components of the most common PSE strain (where group connections also have one final connection, which is the puzzle’s answer) with a variety of connecting methods used in the original BBC TV series, Only Connect. This means that not all groups are of the commonly used ‘linking word which can precede/follow the given word’ mould – bear that in mind!

Also, for this Connecting Wall, you will need to partition a larger number of clues (24 of them) into 6 sets of 4. Once all 6 sets are found, you need to provide a specific 4-letter word that links the 6 connections – this is the final answer for the puzzle.

Good luck!

+----------------+----------------+----------------+----------------+  
|    ASTERISK    |     BEFORE     |     BELOW      |   COMMODORE    |  
+----------------+----------------+----------------+----------------+  
| CZECHOSLOVAKIA |       F        |     GUFFAW     |    HARRISON    |  
+----------------+----------------+----------------+----------------+  
|     ISAIAH     |     LOIRE      |    METAPHOR    |      MILE      |  
+----------------+----------------+----------------+----------------+  
|       MM       |  MYERS-BRIGGS  |      POOL      |     POUND      |  
+----------------+----------------+----------------+----------------+  
|     QUINCE     |    ROBINSON    |   SEMAPHORE    |      SNES      |  
+----------------+----------------+----------------+----------------+  
|     SUPER      |       V        |    WHISKEY     |       XV       |  
+----------------+----------------+----------------+----------------+  

TASK:
(1) Partition this Connecting Wall into 6 sets of 4 clues (various connecting methods);
(2) Find the final 4-letter connection between the 6 connections.

(Note that once you pinpoint a couple of groups correctly, you may gain an idea as to where this is going and be able to find the others much more quickly!)