I've tried with just bigdebuffs enabled in a raiding environment in WOTLK, and I've noticed that every 3 seconds or so, there's a slight stuttering? It can help if I disable the raidframes' portion of the addon, and maybe this is just my own experience, but curious as to whether or not others have similar experiences?

PS. Apologies in advance as I know that this is entirely anecdotal/non-specific.

Thanks a lot - I'll try that out!

Can't say that I do actually. To rule BD out, install an Addon CPU monitor tool/addon to verify the load.
Eg. https://www.curseforge.com/wow/addons/addon-usage

Should give a hint to which addon is causing this.

From my own personal experience, addons like Details, Skada and such - when they aren't configured the right way can cause similar issues. Stuttering and so on.

Finaly, I made a response to a post in the EU forum a few weeks ago regarding this topic too, non-addon related issue, and how I solved it.
https://eu.forums.blizzard.com/en/wow/en/wow/t/is-stuttering-still-normal-for-some-people-right-now/402896/10

Hello,

Not OP but I came here to check about this specific issue.
I actually did the trace yesterday through the addon "Addon usage", as I was convinced BD was the issue.
Capture has been taken in Nax 25 - between 2 packs of thrash (not in fight)
Did check a few times between thrash (but didn't took another capture) for the whole raid duration, Big debuff was always top by far in CPU consumption. I imagine it being even worst during a fight.

The capture is pretty self-explanatory, it's been weeks like this.

Any help on this please ?

Regards,