Hi Sean,
Thanks for raising this on the community! The “Packaged beer current stock” report found in Reporting → Pre-built Production & inventory reports allows you to show stock by location, so if you do not have multiple locations in your sites this might work for you. Otherwise there is the “Product stock availability breakdown by site” report which shows the stock breakdown for a product across all your sites that you could export and remove the irrelevant columns from.
We do have a function to create price lists with stock figures, that is designed for updating your customers on stock, available beers and prices, our guide on Creating price lists in Breww has more information. These still do not allow you to filter to a specific site’s stock, but it would be a great feature, as you have pointed customers can be locked to fulfilment sites so locking price lists to specific sites would be a very sensible improvement. If you would like to see this added, please feel free to raise this as a feature request for our dev team to review. Alternatively, if you would prefer to just have a stock report filtered to a single site, again feel free to raise this as a feature request for our dev team.
If you have any questions at all, let us know!