If by "new firmware" you mean v5.4.5 -
Then you must jailbreak
**before** upgrading to v5.4.5
Installation of additional things is done
**after** upgrading to v5.4.5
(Note: You have to use v5.4.5 to get kindlets to run (which is what KUAL is) ).
KUAL and MKK from NiLuJe's snapshots thread -
https://www.mobileread.com/forums/sho...d.php?t=225030
In general, KUAL extensions are not affected (but some applications, like Collections Manager are).