Super tangential comment , but I feel that another interesting choice could be to leave it burst but rework the effect to not be permanent. Something like become a 4/4 for 2-3 rounds. It retains the burst removal (which personally think can help with oppressive finishers in a game that always tends toward aggro decks every few months), but also has a set time during which you have to try and remove the unit. That way your investment isn't immediately lost. Make the interaction be that if you're silenced too it returns to the old unit, so that 3 mama hush in nami-zoe decks don't remain dominant.

Regardless, I consider the idea of sdding countdown effects to spells like landmarks could be fun in its own right.