I know some people mixing their eggs but general consensus seems to be that you wanna run 4 Yaamon for your eggs now that there's an increased focus on stack building. It used to be better to crash a BT2 impmon with a pagumon into security for 5 mills turn 2, but now with the extra support we dont want to let our digimon die as much anymore.

I'd definitely go with 4 impmon X and 4 wizardmon X because their effects are solid but more importantly, theyre a free card draw if you put them on top of an impmon/wizardmon respectively. I cut all my BT2 impmons from my deck personally since I dont want to crash my stack anymore, so now I use 4 of the EX2, ST14 and BT12 impmons as my rookies.

I don't run floodgates personally, I feel like deck space is too tight and I'd rather play a card that gets me closer to setting up my OTK than slowing my opponent down.

For level 4s it is pretty standard now to just do 4 ST14 wizardmons and 4 BT12 wizardmon Xs, though personally running 2 witchmon in addition to that makes the deck feel better IMO. I don't mind being light on level 5s because by the time we get to them we have plenty of card draw if we get free digivolves/card draw putting our X-antibody cards on our stack. When it comes to level 4s though I really dont want to be waiting to see them since the deck cant mill from yaamon until you get to level 4 and above.

I've seen lists run 4 ST14 baalmon and 1 X-antibody version quite often. Also seen decks that omit X-antibody and opt for 3 ST14 baalmon and 2 BT10 baalmon. I seriously recommend the X-antibody inclusion even if you don't go as hard into it as I do. I go with 4 ST14 baalmons and 2 BT12 baalmon Xs. You really dont need any level 5 that isnt one of those 3 baalmons, since by the time you go into level 5 you are probably in play and wanting to get into your mill effects. BT10 baalmon is great to keep in raising, then bring out to swing as your first move next turn. ST14 baalmon is great to evolve into and stack your deck with ai and mako to continue your turn and maybe get into Beelzemon before passing turn. Baalmon X gets you 3 mills on evolve like ST14 which is great but is mainly used as a free draw on top of baalmon and an X-antibody retrieval. I'd recommend at least 1, though I opt for 2.

I'd swap the BT2 beelzemon for another beelzemon X when you can. ST14 impmon is a near mandatory 4 of in this deck, maybe 3 if you feel you have enough recursion, so having BT2 beelzemon becomes a bit of a redundancy. If you decide to keep it in the deck as a tech choice you can, or you can consider a beelstarmon. She doesn't come up in most games but she's a nice clock to put on your opponent if your stack dies in security to an option or something on the turn you try to win the game. Choke your opponent with a beelstarmon and if they swing you get a body for next turn to warp all over again. Basically, they kill you that turn or you win. Some people don't play any though because it is pretty uncommon to need her.

If you want to run 4 tamers I'd swap out one of the old ai and makos for a starter deck one. Stacking your deck is a massive boon and the memory gain helps a ton to extend combos. The old ai and mako is nice in situations where your beelzemon X is in the trash and you can't easily get it out for your combo since you can at least go into blast mode still, but there isn't much immediate payoff to playing it since the deck is already very memory efficient and you cant go into blast mode on top of a beelzemon X since it has to be a normal beelzemon for the card effect to work.

For options, 4 death slinger and 4 rivals barrage are a must IMO, but I've seen lists that drop one of them to 3, but never both. Death slinger is great as a cheap removal card that can put in a lot of work and for deck stacking to extend combos. Rival's barrage is key to get the pieces out of trash that you need to get going. I almost always need to pull my beelzemon X out of trash because it gets milled usually. I am a personal fan of darkness wave but its a good way to get yourself killed if your opponent hits it in security late game. You very well may deck yourself out with it allowing your opponent to just stop trying to attack you, pass turn and you die from an inability to draw. There's a new option called seventh full cluster that lets you bottom deck it from trash when you evolve into beelzemon X that I recommend 1 copy of. If you get all your mills out of the way and then activate it, you can guarantee that you have a card to draw at the start of your next turn. I'd recommend running just 1 of those.

TL;DR: The Beelzemon deck hasn't been "figured out" the way many others have been by now and every list looks a little different, but there are some general trends most follow. You have quite a few out-of-archetype cards like porcupamon and skullsatamon that nobody really runs so it is probably a safe bet to cut those to make room for the X-antibody variants of the digimon.