question on asset processing tools/information

Are

aif:core:sceneOptimizerVersion | string | Scene Optimizer version
aif:core:assetValidatorVersion | string | Asset Validator version

valid as attributes of a SimReady asset, or are they metadata associated with the tooling/process that created that asset?
I would like to suggest they are the latter. Their values would not impact any downstream use of the asset - they don't contribute to any simulation usecase.

As such, i wouldnt have expected them to be attributes of the asset. Instead, would that sort of data be better represented in customLayerData or assetInfo, where toolchains might place record of actions performed e.g. "optimizer version, settings, validator version, date validated etc."

Also, is it safe to assume that if assetValidateVersion is included, the asset passed validation?

Start by reviewing the SimReady asset definitions for aif:core:sceneOptimizerVersion and aif:core:assetValidatorVersion, then compare the documented roles of customLayerData and assetInfo. The issue is done when the specification clearly states where tool and validation metadata belongs and whether assetValidatorVersion implies that validation passed.