I know it is best practice to shove the higher rated MCBs/RCBOs up towards
the supply side of the bus bar.

However, for new 32A circuits, do people generally re-jig the ordering to
maintain this, or just bung a new one on the end after all the 6A ones?
There would be about 6 to move and it would complicate the existing wiring,
as there is not much slack.

I presume that DIN rail bus bar is perfectly capable of maintaining the full
100A right to the end (it's a 16 way type), and the circuit is unlikely to
be loaded to any extent, so I'm not worried about the tiny potential for any
significant voltage drop. I'm just worried that the inspector will have some
potential set of personal Hitlerite rules that aren't in the regs and I
don't particularly want to argue the toss.

So, do I bother rejigging the low rating MCBs?

Christian.