Help needed - 2011 Jimny violent knocking, shaking, engine cuts out and fuel

The trouble with mifiring on a Jimny is that the usual causes are intermittent and affected by heat, so are hard for mechanics to replicate.  In the scheme of things, the parts are not hugely expensive to change as minimal labour is involved.  If you don't want to pay for new genuine coil packs, there are usually lots on eBay from Swifts with the same engine (M13A).  Just avoid anything that looks filthy, and try to find out what mileage the scrapped car had done.

First port of call should be replacing the crank sensor. It's a very common failure and mostly fits your description of the fault..