What do you play against these triangle defenses in the Closed Catalan

Stupid me decided to study the Open Catalan but forgot the Closed Catalan

People also play bd6 instead of be7 in this triangle defense thing I've noticed

For white, I've seen b3, trying to play a double Fianchetto thing, qd3 which I don't quite understand (I think it's to go e4?) and nd2 + e4

1. are there any other decent moves for white in that position?

2. What are the middlegame plans in these Triangle systems (for white)?

Play Nfd2 before Nc3 and then just play e4. It scores great. Recommend going through some games in the opening explorer for middlegame patterns.

In Closed Catalan here is what you do:

in the Closed Catalan white wants to build a small but definite advantage

of course there is also the Botvinnik way of playing the Catalan (Qd3):

There are more systems as well for the Closed Catalan but these are most simple and effective

There is also one last way of playing as white:

The point is to support c4 with the pawn, support d4 with the rook and play e4 with the support of the queen and knight.

Watching this setup, this ideas seems more practical in regards to the closed Catalan. slowly expanding and controlling the center. Plus you have a slight initiative on your side. Black will soon have to play wandering moves until he can react your piece maneuvers.

As you will see black in these "triangle" systems will almost always follow up with b6 Bb7

In the chess.com master database after 8.Nc3, white scores 85% wins, not including draws. Actually I think black has only one win after 8.Nc3, and it was because white threw the game.

Exactly, I'm pretty sure black is just reacting after this move order. Unless black can create some counterplay black will forever be slightly worse in this position.

I don’t have faith in crickets move order to be honest, it looks much too slow to pose any problems. For example black had many chances to play for e5 or c5 but did not.

Ok this looks convincing but...

Also if c5 wants to be played earlier then just play c5 instead of the Triangle System. 

Like this:

I've usually just been playing this I think

So B1Z's suggestion but with a different move order (is that a bad thing?). I've been playing e4 and then after that, I think what i'm probably doing wrong is trying to attack black's kingside (dont ask me how I don't recall)

If you play Nc3 first you have to deal with annoying dxc4 right after 

Doesn’t dxe5 followed by cxd5 just grab a free pawn 

I’m not sure why white would ever want to be the first to release the tension. Nf3 Nc6 then O-O and after dxc4 I don’t remember the move but it’s either dxc5 first or Qa5 first which makes blacks life difficult. I could grab Avrukh’s book but I’m mowing the lawn right now lol

yes but black gets compensation

and anyways I took the idea from the engine so yeah...