fix(delete-user-data): kit/extension parity – kit sets no maxInstances, so functions cap at 100 instances #3311

delete-user-data kit/extension parity. Priority: medium. The kit's functions can scale to 100 instances each, against 3000 on the extension.

Difference

• Each function runs one event per instance (concurrency: 1, from fix(delete-user-data): kit/extension parity – kit silently skips deletions under load (concurrency 80 OOM) #3250), so the kit handles at most 100 deletions, searches or discovery batches at once per function, against 3000 on the extension.
• Not tested: how a burst past 100 in flight behaves. The README says Eventarc redelivers events that hit no available instance.

The same difference is tracked for storage-resize-images in #3275.

Code

• Extension: 1st gen resources with no instance settings (extension.yaml#L59-L87).
• Kit: the shared runtime options set concurrency, CPU and ingress, but not maxInstances (index.ts#L118-L122).
• README documents it as a remaining difference (README.md#L246-L250).

Resolution

• Set maxInstances in EXTENSION_RUNTIME_OPTIONS, so all three functions get it. Pick the value with fix(storage-resize-images): kit/extension parity – kit sets no maxInstances and allows all ingress #3275 so the kits match (fix(kits): match the extensions' Gen1 concurrency and ingress #3206 uses 500 on syncBigQuery). A per-function value overrides setGlobalOptions({ maxInstances }), so users could no longer change it that way.
• Update the README paragraph above.