@gutocmtt I agree with this completely. Bant/Stony build is consistent, has good mana, good plan against shops in the SB, tries to dodge Tinker/Mentor from PO. Grudge build has greedier mana, should dunk on shops, has a reasonable plan against PO, still tries to dodge mentor but can red blast tinkers. BUG versions are weakest vs shops (still not bad though!) and have a delver-y plan against most of the field. This versions feels strongest against PO, Oath, and the mirror.
as far as innovation goes, there is probably some small tuning you can do for each of these, but improvements will be in the margins. The core is definitely very powerful and the flex cards can be adjusted to fight various metas.
if you want to take the deck in a slightly different direction you could build the flex cards to be more proactive and combo oriented. A card that hasn't been mentioned much that is very powerful in conjunction with survival is Lion's Eye Diamond - you can crack LED with a survival activation on the stack for a pile of VV's. Heavy crop rotation builds could also be viable as in a Bazaar focused deck. You could also maybe try for a dredge/survival mashup?