Today these 3 fields appear in the JSON final but are absent from the 83B
descriptor. The 11-byte 'reserved' block has room for all three (4+4+1=9).
TODO section now proposes concrete encoding lines:
8|latitude|hex2dec|degrees|x/1000000|
8|longitude|hex2dec|degrees|x/1000000|
2|misc|hex2dec|||
...with an open question on whether Miotiq hex2dec supports signed ints,
and a note to keep 2 bytes reserved for future growth.