Hey ,
Have you tried changing the settings within the Pin Visibility within the View menu? You can select it to either Hide Unused Pins or Hide Unconnected Pins. That may help with a combination of collapsing some nodes.
Unfortunately, I can’t find any setting within the editor to give more power to it. However, within your Windows Task Manager, you can right-click on the Unreal Engine and set the priority, which may make it run more smoothly for you.
When you say that when the blueprint starts to lag, the project starts to lag too. Does that mean that the project lags while the blueprint is open, or it still lags once it’s been closed?
Thanks!