The only time we have ever seen an infinite mana issue was with Sn1p Sn4p costing 0. Sure there have been lots of decks that make huge reductions in mana and mechathun is one key card to have concern of going down the track. Though if an aggro deck can win by turn 4 or 5 then I don’t see why you can’t have an OTK deck win by turn 5 on a high roll. IMO dev’s need to leave these kinds of decks alone until they really are game breaking and win on turn 3 for example and until they actually have win rates that can’t be achieved with other decks.
I haven’t seen the deck yet even (though I understand it very clearly) so I can’t pass judgement on it from an experience perspective of playability.