I'm having some latency on my druid right now. I checked the menu bar to see what's eating memory, and I see HeroLib steadily ticking up even though I'm just standing still. It was 38mb when I was watching it, and now 40.3 and still going up.

I reloaded. It dropped down to 28mb and started ticking right back up again as I watched. It's going up at .01 or .02mb per second.

8.3.0.00-19-g1ecbe47-alpha

Update: Just downgraded to 8.3.0.00-18-g53d23e6-alpha, logged in... now seeing it tick up .03-.04mb per second. ><

This should not really be the cause of any latency. This is generally just how Lua memory management in WoW works. 40mb is not really anything that would make any impact on performance as well. You generally would want to look at CPU profiling rather than looking at memory usage, since CPU usage is really the major factor for framerate in-game.

Not sure if I can really describe it well. Latency was the wrong word - more like stutters in the game when interacting with things. My CPU isn't hitting above 15%. RAM is running ~50%. I mouse over the Game Menu button to see the tooltip; FPS shows 60 initially, then drops to 52 with the game doing a per-second "hiccup", and with each hiccup HeroLib ticks up. It was just suggestive of a link and I thought I'd bring it up in case.

The stutter might come from GC cycles. I recommend you to upgrade your CPU / RAM because it was not normal.
Although, with 9.0 rework I've improved a lot the memory management and you should not feel any of those stutter if they were coming from HL.