A couple of things:

1. I wonder why/when Query.getReturnAliases() was removed. Does anyone recall?
2. I believe it very likely that the AIOOB bug is fixed in my pending PR here: https://github.com/hibernate/hibernate-orm/pull/6685/files#diff-8138079eb60e4f269c1ffe8ead003a5ad05f1850b35ba9084079c2c249a87e08

It might be nice if you could try out that patch and confirm that for me.