Warning notice on dash

[Rwg]

Hi Just a post for some insight regarding title above.

Around 8,30pm I got the notice on dash
Brake servo Restricted
You can continue to drive !!!
Contact work Shop

Seeing that it was 8,30pm, I then hit Internet to find out more. All good advice but some very worrying in regard to continuing to drive.

Google found booster sensor on Amazon, ordered 11,15pm arrived next day at 1pm wow. ( cost £13 inc delivery)
Fitted same part 5 mins found to be all correct.
Deleted codes and test drove car 30 mile brakes back to normal all good.

Went to Euro parts to see if they had one following day, thinking check to see if I need Original VW AG part.
They did not have one but next day £169 !
Will contact Audi to see what they have to offer, I will most definitely get a second unit as I would not like to drive car for a distance that could cause ABS to fail
Interested to know any similar experience with 2019 rs4 b9
Cheers