Microsoft project management software used to plan, manage, and communicate a project schedule and other information among workgroup members, project managers, and other stakeholders.
Dear Gabe Lebin,
Good day! Thank you for posting your query in our community.
Per your description, you want to change the location for saving uploaded attachments in Project for the web.
Based on my research and test, honestly, this feature is not available yet in Project for the web. The file storage structure in Project for the Web is tied to the underlying SharePoint site, which is designed to organize files at the group level. Therefore, all files uploaded to tasks within a particular group's project will be stored in the same Documents folder. As a result, files from different projects within the same group will be bundled together inside that folder.
In this scenario, I suggest you can raise this idea on Project UserVoice at your convenience which it can let the related product team aware this limitation and improve it in the future. Sorry for the inconvenience caused.
Appreciate your understanding.
Sincerely,
Jazlyn | Microsoft Community Moderator