[Help] Mac Pro 6,1 (D500 Dual GPU) - Constant Lag, Red Glitches in Chrome & Stability Issues on Sequoia

Hi everyone,

I’m reaching out because I’m at my wits' end with my Mac Pro 6,1 (Late 2013) running OCLP. I love this machine, but the experience has become a "karma" of instability. Here are my specs:

• Model: Mac Pro 6,1 (Trashcan)
• CPU: Intel Xeon (Standard)
• RAM: 48 GB
• GPU: Dual AMD FirePro D500
• OS: macOS Sonoma (currently using OCLP 2.4.1)

The Issues:

1. Visual Glitches: Chrome and other Electron-based apps show "red blocks" or artifacts.
2. General Lag: The UI feels heavy, windows stutter, and there is a noticeable delay when opening apps.
3. Stability: The system becomes unresponsive during hardware-intensive tasks (like running local LLMs via Ollama).

What I’ve Tried So Far:

• Updated to the latest OCLP (2.4.1) and re-applied Root Patches.
• Attempted to disable one of the GPUs using -wegnoegpu in boot-args, but I ran into "Error setting variable not permitted" (SIP issue) and UI limitations within the OCLP app (the NVRAM tab or Advanced settings aren't showing as expected).
• I work remotely on this machine, so physical intervention (like removing a GPU) is a high-effort/high-risk last resort.

My Questions for the Experts:

1. Is there a specific stable OCLP version or configuration known to work better with the dual D500s?
2. How can I properly disable one of the GPUs in OCLP 2.4.1 specifically for this model to test if one card is failing?
3. Are the "Red Chrome" glitches a known driver issue with Metal translation on Sonoma for these specific AMD cards?
4. Should I give up on Sonoma/Sequoia and revert to Monterey (Native) to maintain stability for local AI (Ollama) work?

I really want to keep this Mac Pro alive, but I need it to be a reliable workstation. Any advice from fellow 6,1 owners or OCLP devs would be greatly appreciated.

Thanks in advance!