Can you combine Polearm Master, Tunnel Fighter, and Warcaster (with Repelling Blast)?

We have a player who is playing a Fighter with a level of Warlock, wielding a polearm, and they say they should be able to get the initial opportunity attack from Polearm Master when a foe enters their reach, then if the foe continues to move in they proc the Tunnel Fighter opportunity attack, which the character uses for an eldritch blast with the Repelling Blast invocation, knocking them back 10 feet…and then could hit them with Polearm Master again if they continue to advance.

Is this legal? I know the Polearm Master feat specifies (according to Mearls) that the opportunity attack from it has to be with the same weapon being used when the opportunity attack procs, but there seems to be no such limitation on Tunnel Fighter.