Some questions about the HRT module

I’m learning the HRT module of PX4.
My understanding is that when the standard used is fmuv5, the value of HRT_TIMER is set to 8, which indicates that STM32_APB2_TIM8_CLKIN will be used as the clock source (HRT_TIMER_CLOCK), is this true?
My question is whether other APBs (e.g. STM32_APB1_TIM3_CLKIN, STM32_APB2_TIM1_CLKIN, etc.) are no longer used (not in HRT nor elsewhere) when STM32_APB2_TIM8_CLKIN is set to HRT_TIMER_CLOCK?