I have a similar age SD4 Auto with EPB, but I tried today to replicate your fault, but I (am happy to report) had no jolting or noise.

Normally I tend to only apply EPB whilst my foot is still on the brake, and then use the automatic release that occurs as you apply the accelerator. I did note that the EPB would not release via it's switch when in neutral unless I put my foot on the brake (as instructed by a message that appeared on dashboard)

If the fault (especially the noise) keeps occuring, I think that you should think about having the autobox flushed, and it's valve block cleaned as suggested above.

https://www.google.co.uk/search?q=aisin+ge...nt=gws-wiz FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Thanks Kage and Ian, will get my mech to change the g/b fluid and do the update, hopefully that will sort it.
Went for an appointment today- about 10 mile4s and it behaved perfectly, both with the EPB and footbrake!
Cheers, Dave