Custom Sharing via QuoteShare for Account Owner Changes - Flow or Batch Apex?

Hi everyone,

I need an architectural sanity check on a security requirement. I want to avoid hitting platform limits down the road and would appreciate some feedback on whether this can be safely achieved using Schedule-Triggered Flows or whether Scheduled Batch Apex would be required.

Context

• We are changing the Organization-Wide Defaults (OWD) of the standard Quote object from Controlled by Parent to Private.
• We receive an integration feed from an external system that creates or updates up to approximately 80 Quotes per Account per day. Quotes can also be created manually in Salesforce.
• Quotes contain two custom Account lookups: Sold-To and Bill-To.
• We have both Quotes with and without Opportunities.

Requirement

• The Account Owner of the Sold-To Account and the Account Owner of the Bill-To Account must have Read-Only access to the related Quote.
• When the Account Owner changes, access to the related Quotes must be updated accordingly, including removing the previous owner's access and granting access to the new owner.
• The required access is managed through QuoteShare records with RowCause = Manual.

Architectural Question

Given the expected Quote volume and the need to automate the insertion and cleanup of QuoteShare records following Account ownership changes:

• Is this approach feasible using a standard Schedule-Triggered Flow, or would Scheduled Batch Apex be required to ensure scalability and avoid governor limits?
• What would be the cleanest architectural pattern for handling the cleanup and creation of Manual QuoteShare records when Account ownership changes?

Thanks for your guidance!