It seems the export in PL8 with Reshape Fusion is not properly working when the denoising is set to “Standard Instant render”. With any other denoising method, the export seems fine so far. I will further test.
In my original test I did not enabled any PRIME or DP* denoising.
Knowing the above limitation, it is not a big issue for me (I typically always use RAW denoising), but it remains a bug.