Anyone recommend an independent repair shop I can post a jacket to for repair as Jack Wolfskin said to go back to the retailer?

Cheers

Alpkit do repairs

If its not a major rip I've had good results with Tenacious Tape in the past.

Cheers,

I had an incident with a down jacket touching a wood stove on a hot tent trip, I sent it to Alpkit for repair but wasn't overly impressed with the work, a glued patch would've been neater I think.

Had a look at the tenacious tape and look like an ideal solution to avoid being without the jacket for a few weeks.

Gaffer tape or zinc oxide have all done me proud, previously. Thriving on the tramp-vibe

I have a cheap Aldi down gilet I use for camping that's got a few duct tape patches but functions just fine. If it's a jacket you like a lot (or cost a lot) then get a professional repair I reckon.
I asked on here about a DIY sole repair on my Altberg boots and was persuaded by the knowledgeable folks to send them to Altberg for a proper fix. It cost a few quid, but I'm glad I did as they came back looking like new.

How big a tear are you looking to fix?

I used these to repair a 5cm tear in my Rab down jacket about 4 years ago and still holding up fine:

https://amzn.eu/d/ioH833E

Spinnaker tape is very good stuff. Available in a range of colours, very sticky and thin so it moves well with its host fabric.