Odd composition behavior with shareable + override

### Issue Description

Context: https://discord.com/channels/1022972389463687228/1186820499867705476/1186820499867705476

Repro branch:
trevor/repro-shareable-override

### Link to Reproduction

n/a

### Reproduction Steps

pull down branch, run test (`npm t -- override.compose`)

Check out the repro branch trevor/repro-shareable-override and run `npm t -- override.compose` first. Inspect the failing composition test and compare the shareable and override behavior, but the issue does not state the expected result or identify a source file; done criteria therefore need clarification from the linked Discord context.

Written by the indexing model from the issue text.