Nice to see this thread active again.

That really is the sad truth about belcher it is an all-in deck.

You can devote about just about 4-8 slots of Sideboard hate for blue, because you really can't change much in the main deck.

Going with a transformational sideboard to grind against blue like carpet of flowers, by doing this I think you are just becoming a worse TES/ANT deck. So it will be better to just switch to that deck as they combat blue better.