[Devvit Web] "height: tall" not respected for inline posts on Reddit mobile app (iOS/Android)

[11ewis]

Summary
Inline webview posts configured with "height": "tall" in devvit.json render at a significantly smaller height than 512px on the Reddit iOS and Android apps. The post appears short/clipped in both the feed and on the post detail page.

Expected behaviour
Post renders at 512px ("tall") height inline, matching the behaviour of the old addCustomPostType({ height: 'tall' }) Blocks API.

Actual behaviour
Post renders at a noticeably smaller height (~350px or less) on mobile. Desktop appears unaffected.

devvit.json config
"post": { "dir": "dist/client", "entrypoints": { "default": { "entry": "index.html", "height": "tall", "inline": true } } }

CSS approaches tried, all fail on mobile

height: 100% on html, body, #root (per official template)
height: 100vh
position: fixed; inset: 0 on body
window.innerHeight read at runtime as explicit px height
Hardcoded height: 512px on all elements
Additional context

Posts created with the old addCustomPostType({ height: 'tall' }) Blocks API render at the correct height — this is a regression specific to the new Devvit Web post type
@devvit/public-api version: 0.12.17
Reproducible on iOS Reddit app