Corby's right about the move towards new rendering systems. They cost a lot more, but save on specialist skills by being sprayed on.
(They've come on a long long way from the old "Tyrolean" spray-on systems of the 60s-80s.
If you want to stay traditional, good old sand & cement can be made non-crackable by fixing galvanised steel expanded metal sheets to the wall, and rendering over.
Years ago we would use 'chicken wire' over cob walls to render them.
Expanded metal is a far better product.
I know you like a bit of 'tradition' OG, so there's one remaining system I could mention.
Lime rendering.
Cracks 'self-heal'. These days it's usually supplied as 'lime putty' in tubs.
Tip it into the mixer, whip it up, and trowel it on.
It's a lengthy job - but it still works.