ACID3 test failed with 99 points when frameFlattening is enabled. Report shows "Test 46 failed: expected 'none' but got 'uppercase' - case y1 failed(index 29)
@ap - Do we need to track this? https://wpt.fyi/results/acid/acid3/numbered-tests.html?label=experimental&label=master&aligned Test 46 passes and as for 'frameFlattening', I think we still have 'frameFlattening' code.
Alan tells me that even though there are vestiges of frame flattening support in the code base, it's not actually supported any more, so this issue is obsolete.