Thanks for replying!
One of the users on BG3 Reddit showed me that tip to use Task Manager to identify bottlenecks. In my case, it was the CPU
In terms of the hard disc space I created 160gb free and it seems to not fix the problem before I upgraded my CPU.
So I upgraded it (new CPU and Motherboard) in, and now it works like a dream.
I shared it with the reddit community for discussion.
One other thing (with your interest in DMing) I would be keen to advocate for is to have a Dungeon Master Client. Should be a no brainer. It would take only a small amount of effort to implement and would multiply replayability by a huge factor, even if BG3 never has the custom toolset from NWN (I don’t think they want to do this, as they have employed all these voice actors, graphical designers and story writers – they probably want to keep them in a job I assume). They have feedback sessions on Reddit, but if there is anyone else out there who thinks that is a good idea, one can always send feedback directly to them via this link.
Some people are afraid of their virtual characters dying or being in danger (we all have different fears) – this could be a non-gaming partner or something like that – if they are the dungeon master they obviously can’t die, and this could open up a more enjoyable experience for them without having to challenge that fear.