I'm just experimenting with new setups of Debian for audio. When running
RealtimeConfigQuickScan it triggered a vague recollection of a
discussion (here?) that configuring hpet and rtc timers is no longer
necessary as they are not used any more. Is this true or am I
misremembering?

The wiki guide at https://wiki.linuxaudio.org/wiki/system_configuration
is still a goldmine for setup but it contains some sections of which I
am unsure whether they are still applicable, including the HW timers bit.