WOFF Over The Top, with its new cloud rendering and terrain rendering up to 150Km, as well as the new weather system and atmospherics, is naturally much more CPU and GPU intensive.
So of course it requires significantly more CPU processing, GPU usage, and memory use to achieve this compared to BH&HII.
In terms of running in a similar fashion to the old BH&HII we recommend:
Scenery Density : 1 or 2
Terrain Detail : 1 or 2
Render Distance: 50km or max 75km
Weather Grid Res : 1
Weather System Max Size : 2
Cloud Render Density : 4
As a base start. You can increase settings slowly once it's stable, to get to your sweet spot.
To run at the higher settings available now you really need an up to date sim rig of course.
Also note not necessarily the highest settings may be useable by all as there is some future headroom in there too.
This is recommended to start with these settings initially if you find missions drop out or quit early.
Also see the FAQ Section 77:
"A Guide to New WOFF OTT Expansion’s Lighting and Weather Settings by Gecko"
on optimising and what all those new settings do.
Our Website Support Page page has the FAQ. Direct link to FAQ:
https://www.overflandersfields.com/index_html_files/FAQ_WOFF_BH&HII.pdf