Is it necessary/advantageous/required by the regs to fit a cable
outlet for an integrated oven?

I always prefer to fit a cable outlet, as when the cooker
is replaced you're not having to chisel the cable running
to the CCU, you're just replacing the drop cable from the
cable outlet.

may just possibly help if I say (i) the On-site Guide says that means of
isolation must be provided for every item of equipment, pointing to

Means of isolation is the Cooker Control Unit. The Scullster is asking
about a Cooker Connection Box/Cable Outlet Box/Cooker Terminal Box.

the stove, a cooker control unit within a couple of meters is preferable
to a dash to the consumer unit.

I had one customer who insisted the CCU should be hidden inside a
floor cupboard. She wouldn't take "that's not allowed" as an answer,
so I patiently took her through the steps of what would happen if
she got a shock and couldn't reach the consumer unit under the stairs
while stood in front of the cooker in the kitchen.

JGH