I’ve checked and confirmed that these are flowing through as expected to Photo WX.
The Environment Canada Astronomical Seeing forecast is now available at hourly intervals instead of every three hours, as had been the case until now, per an announcement from the MSC Datamart mailing list last week.
The transparency forecast was previously available at hourly resolution, so this change brings things into alignment.
You can read the model documentation here: Readme astro rdps datamart alpha en - MSC Open Data / Données ouvertes du SMC