Definitely start with one. Customs add density, and adding them to a stack is a game of fine tuning the balance.
What I would do is take two out of three of the titles currently in your stack, make a custom of them, and replace the two titles with one custom.
Then just run a two title stack for a while.
Go from a 3 title stack of (RMUWX / HeO / LBFH) to the two title stack of (RMUWX / LBFH+Heo)
Even that will add density and exposure. Not only because customs are heavier and hit deeper, but also because you may listen to the same amount of cores more frequently because it’s two titles.
One thing you could even do is start with just a one core custom, probably LBFH, because you’ve gone so deep with LBFH already and feel like you’ve kind of reached all its objectives. A custom will make LBFH stronger and help you hit new heights with it. Add in DEUS to enhance that effect.