Single ring does not comply with 314.1, may not be "balanced" re all
kitchen loads at one end. Many councils will reject a single ring
based on the latter.

Breaking into two 20A radials doesn't gain much.

20A radials are good in quantity - that is one per room (lots of PCs,
rented) and multiple in a kitchen (fridge/freezer, washer/kettle,
dryer/microwave, fan heater). Quantity provides redundancy and
localises any earth leakage fault (cable fault, element fault). 20A
radials have a safety benefit in that a 2G socket is limited to 19.5A
continuous, whereas downstream protection is 13+13A and upstream CPD
on a ring would be 32A. The benefit of a radial is topology - whatever
you want.

32A rings are good in quantity - minimum of two unless you know the
ring will be balanced (not likely). 32A rings have a safety benefit in
that there are 2 paths for earth, so effectively reducing EFLI
although that is less critical with RCD protection. The downside of
rings is the topology must be a ring, not always easy in some houses
(and decoration!).

32A radials are a good compromise using 4mm FTE - still rare in
domestic, but practically very useful in a kitchen environment. Note
that Grid Switches are limited to 20A circuits, but then I suspect a
kitchen could have a single 32A isolator re "emergency isolation" or
isolation for all appliances (burning microwave, removal of built-in
appliances).

I personally prefer lots of 20A radials re 314.1 redundancy,
topological flexibility & expansion flexibility.

However for the OP I would break the kitchen off into its own 32A ring
for 314.1, then have the house on its own ring. It might be very
convenient physically to do this.