He wouldn’t have had access before his second appearance, since the Ultimatrix was linked to the Omnitrix he had access during the final battle part 1,if he just instantly went to Waybig he could’ve destroyed the biods and could’ve gone ultimate, though his goal was to obtain the Omnitrix to reset its catalog to the original 10 so he could access Greymatter, , another reason why he probably didn’t use Waybig was his arrogance in the power of the Ultimatrix.
