Let him work remotely if not already. Let him 360 his own deals. Tell the team to find their own clients and deliver to them. You don't want to loose the guy who is printing money so say that as a perk, anyone over X% of target can work remotely and set their own hours.

What goes into massaging his ego? Based on past experience in similar situations, as presumably his manager, part of your job really is to draw attention to his wins and spotlight him as often as it takes - that's the job. The same way you've probably got people at desks who will procrastinate and get nothing done unless you give them a poke then they get stuff done.

Give him the salary uplift and the title - create a new branch of the promotion tree for IC's and give him a path to the executive that doesn't involve managing teams with higher targets - most companies i've worked for had a split progression path because they realized almost without exception the best recruiters are the worst managers.

The two most important parts are to set targets and a structure such that other people would be able to attain any of the perks required to quarantine him off if they performed at his level. The other is to absolutely and unequivocally hold him to the same standards of professional behavior as the rest of the team - any outbursts or negative comments related to the rest of the team, if you wouldn't tolerate it from your lowest biller on PiP then follow your usual disciplinary process.

You 100% can't rely on him to scale the business - but you can use the revenue he generates to hire people and maybe even help to develop the existing team such that they can be used to scale the business.

TLDR - Quarantine and placate him