Hi Jake,
I'm in the same situation, I cannot use the brightness control after install 10.12.6.
DELL Latitude E7250 - 12,5" 1920 x 1080 - Intel HD 5500 - mac OS Sierra 10.12.6 - BIOS A19
Which Bootpack should I used ?
E7450_HD5500_Only_A19_HS.zip
E7250_A19_HS.zip
Many Thanks ~~~