Dr. E, you highlight a good point. There are things that happen or are good to do but ICAO doesn't specify it in SARPs or PANS. Does that mean we shouldn't do it?
Maybe that's why the UK has gone further than ICAO. The UK's CAP 413 says
The ATS messages listed below are to be read back in full by the pilot/driver. If a readback is not received the pilot/driver will be asked to do so. Similarly, the pilot/driver is expected to request that instructions are repeated or clarified if any are not
fully understood.
Taxi/Towing Instructions
Level Instructions
Heading Instructions
Speed Instructions
Airways or Route Clearances
Approach Clearances
Runway-in-Use
Clearance to Enter, Land On, Take-Off On, Backtrack, Cross, or Hold Short of
any Active Runway
SSR Operating Instructions
Altimeter Settings
VDF Information
Frequency Changes
Type of Radar Service
Transition Levels
Now maybe it's undesirable to deviate from ICAO but in something like this I'm 100% behind the way the UK has gone and expanded the ICAO words. Perhaps you don't completely agree with the UK rules but if they are followed within the UK there will be fewer misunderstandings.