Since minor version 42 (the introduction of coroutine), memory usage (and especially spikes) have gotten pretty severe. I've witnessed a 2 orders of magnitude increase between version 41 and 42 at the top end. This is a constant big spike->collection cycle.

I'm not sure if this is just a calculated side effect weighed against the benefits, but just thought I'd let you know.

How are you measuring this?

By running a couple addons that include LibGetFrame in a high unitframe environment (AV) with AddonUsage also running. Then swapping between versions 41 and 46 of LGF with nothing else changed and seeing (sometimes significant) memory differences. One addon's memory increased 10-fold from ver 41 to 46 (I put an issue in with them as well).

idk much about all this, was just something I noticed and tried to track down the cause

It's normal that the lib use more memory while scanning, with coroutines it takes a few frames to finish build the table, so it has to do that in a temporary table to not have partial results during the scan.
It's a memory vs cpu tradeoff.