OP-Thanks for bringing this here. Saw you there, and as best recall, the standard non-oil related explanations as to why this is happening came up.
Interestingly, some there think that a thinner oil might be beneficial or prophylactic? (insert sophomoric replies. LOL). Rationale being quicker pressure-up of the VCT system when cold? I have no clue, just passing along a theory.
FWIW, sludge has not been implicated in most of the cases of this EB problem as reported there. 🤷ðŸ»â€â™‚ï¸