Preflop trees with many players tend to get very large. It is therefore strongly recommended to build sparse postflop subtrees to reduce computation time and allow less card abstraction. Begin by building the preflop tree, with an empty postflop tree. Save the tree so you can easily revert back and try different postflop settings.
Sparse postflop trees can be created with the following filter. Right-click the root node, choose "Add to all->custom filter."
A single, relatively large betsize is recommended. The tooltip of the "Cold call" setting reads: "Do not add calls when x or more players are left to act". With 1 set, this will ensure only 2 players make it to the turn (unless checked around). Donk bets are also excluded to reduce the tree size.
You should also consider removing preflop options which are not very important, yet bloats the overall tree size, such as flat calls by the small blind.