Yes, just report few of their posts, and in the report message mention that the user is mass-spammning, moderators with their available tools should easily identify them and take appropriate action on the user. (has happened before).
since the reports are reviewed by actual people and not bots or AI, i think even reporting one post and mentioning mass-spam should result in moderator taking a look at that user's profile and check out their other posts.
I do wish that we could report a user's profile as well. for example something in their bio, profile picture etc.
I reported that user's posts already, but moderators don't usually take any actions during weekends, but since today's Monday, those posts should be removed.
there is also an Email: techcommunity@microsoft.com