Poor performance of Generals on modern hardware, and multi-screen problem

Bought C&C Generals as part of the ultimate collection. Have two major problems with it:
1. Doesn't work with multiple screen setup: when trying to pan left the mouse often just goes on to the left screen and doesn't pan. Makes it unplayable.

2. It runs under 20fps on a 3070/5800x at 1440p high settings.

Can either of these be fixed?