Last year when I knew even less than I do now, in late October I
pruned a very leggy cistus - not drastically, but as much as I could
without cutting back into the wood.

In fact it seems to have responded well to that treatment but I've
since learnt that cistus doesn't like to be pruned and am wondering if
this is something not to be risked again?

If I take the plunge again, would it be better to prune after
flowering (that'll be soon) or is autumn a safer option?

thanks if anyone can enlighten me.