Looking for some help or suggestion on best practices here.

I have an animated alembic file from another DCC.
The alembic itself isn't too bad, 200MB. Containing about 800 frames of CAD based transformation animation. The base model is fairly poly heavy, but there's no deforming geometry.

But in Solaris, animated/packed alembics doesn't seem to play well. I'm unable to load the alembic directly as asset reference of via the File LOP. From SOPs, packed alembics doesn't display or render. I am able to load and render using the Sublayer LOP, but that doesn't work well with the scene setup and need for multiple instances.

If I unpack the geo and try to export as USD (as asset or directly with the scene), I run out of memory and crash. I assume because it's baking and loading every frame to memory - and naturally the output file is huge. I can bake/save limited frame ranges, but just exporting 30 frames gives a 2GB USD file. Since it's just transform animation I hope there are better ways to handle this? The goal is just to reference the animated file, apply textures and instance it in a couple locations. Keeping things light weight.

Any suggestions are appreciated! Thanks!

You can tick "Flush Data After Each Frame" in USD_ROP to avoid out of memory situation. But you'll end up with huge file anyway.
I'm struggling with similar situation. I have 40 frames of car animation in alembic file. Geo is about 900mb, no deformations. I'd like to get one usd file with geo, and second one with transformations. But all I was able to get is a sequence of 40 usd files, about 900mb for each frame of animation. I stitched them using "usd stitch" node to get one large usd file. It renders fine, but it's far from perfect or even good solution.
There's also "usd stitch clips" node, but I haven't gotten it to work yet.
You can take a look at:
https://www.tokeru.com/cgwiki/index.php?title=HoudiniLops#File_per_frame [www.tokeru.com]
Maybe you'll find something useful.