As long as the dairy farm compost has been hot composted, it should be fine to add it to your community garden beds.  Hot composting kills parasites and reduces seeds from weeds.   Here is some information from Oregon State Extension about using animal manures in compost in gardens - https://extension.oregonstate.edu/news/turn-manure-compost-your-garden

You would not normally want to add sawdust in your garden bed soil as it would compete with the plants for available nitrogen as it breaks down.   If you still wanted to use it as a mulch, you would need to add additional nitrogen.  Here is an article from Lincoln County Master Gardeners on this subject - https://www.orcoastmga.org/single-post/using-sawdust-as-mulch#:~:text=Sawdust%20or%20shavings%20can%20be,that%20needs%20nitrogen%20to%20decompose.

Sawdust can be added as a carbon source to cow manure in the compost pile as part of the hot composting process.