There is data SB-based spin pauses are less disruptive then ISB-based one on them, so performance is better:
  - https://github.com/mysql/mysql-server/pull/611
  - https://github.com/facebook/folly/pull/2390

There are discussions regarding using it for spin pauses:
  - https://github.com/gperftools/gperftools/pull/1594
  - https://github.com/haproxy/haproxy/pull/2974

Instruction support: https://developer.arm.com/documentation/109697/2025_03/Feature-descriptions/The-Armv8-5-architecture-extension

Speculation Barrier FEAT_SB introduces a barrier (SB) to control speculation.
This feature is supported in both AArch64 and AArch32 states.
FEAT_SB is OPTIONAL from Armv8.0.
FEAT_SB is mandatory from Armv8.5.