I played a variety of MKVs, remuxed from UHD Blu-rays, and also UHD Blu-ray m2ts files. I checked them all with MediaInfo first to make sure they have all the usual HDR metadata, including MaxCLL and MaxFALL.
I can see the Infoframe values Vero outputs, and MaxCLL and MaxFALL are both a string of zeroes instead of their proper values. Other metadata, such as PQ and color primaries information, are passed intact from Vero to TV.
I tested another media player in the same set-up, using the same files. It passes all metadata, MaxCLL and MaxFALL with proper values included, from source to TV.