Residents and others will have until June 10 to comment on a controversial affordable-housing development on Brush Hill Road, according to a letter from the Massachusetts Housing Finance Agency. The proposed 276-unit development near the Fuller Village retirement community has prompted objections from many Milton residents who fear the large development could worsen traffic, harm wildlife habitats, and increase town expenses. The original period for submitting public comments to MassHousing had ended March 30. Because the project is moving forward under the state’s 40B law, which allows developers of affordable housing to bypass local laws, the decision of Milton’s zoning board is subject to appeal to the state housing authority. Following the comment period, MassHousing will determine the feasibility of the 40B application.