Sandiego
We used to open them during the landing flare and then leave them open.
The micro-turbo for engine start was in the left air brake bay so having them open made the next engine start possible.
Doing that made it easier than someone having to use the electro-hydraulic pump to open them.
Now, it’s been over 13 years since I last flew a Jaguar but my explanation sounds plausible. Let’s see if Cattechie agrees with me!
BV