Considering the amount of posts he makes, it's true that manually reporting every post will only waste our time. Reporting a few of his posts and then putting him on the ignore list is probably the best way to go with.
But if you don't report his posts, his account will not be banned. If you want him to be banned, keep reporting and you can visit his post history page like once a week, to report all his spam post. It can take you some minutes to do it each week if you feel that account is very bad for the forum.
I had several successful reports regarding this user, but my last 3 reports from ten days ago are still unhandled. Obviously, there are different criteria among mods, because the only message that these spammers understand is as many deleted posts as possible, followed by a temporary ban.
Many reports, many deleted posts contribute a first temporary ban. Many temporary bans cause a permanent ban. It's the flow of spammer to Archive bin of forum.
If that doesn't make them understand, there is only one more option, but a permanent ban due to spam is something that is hard to expect.
The rule is only 3 temporary bans, and a fourth one is a permanent ban but if a first temporary ban need like 100 or 200 spam posts to be executed, a permanent ban with spam reasons, maybe will need up to 400, 800 or 1000 spam posts, that is unbelievable. I agree, it's hard to expect a permanent ban on a spammer.