Not saying speccy is to blame at the core of the issue, but after troubleshooting audio latency spikes for weeks, it dawned on me that the spikes were every 3 seconds, and I have speccy always running in my tray fetching temps every three seconds. closed Speccy, spikes gone. That's all I know for now.
Asus ROG laptop, connected to power, tested with and without battery.
Ticket submited with speccy snapshot and screenshots, thanks guys. I do believe power management within my 'performance' laptop is probably the heart of the issue, but despite troubleshooting all variables, seems that closing Speccy is the only way to completely resolve the latency issues, which I've now noticed occur whether Speccy is in tray or not, fetching temps.