Playing on Vulkan with a GTX 1080 and latest drivers, no issues at all.
Added Valheim.exe to Nvidia 3D Settings and made sure Vsync was disabled there.

Running with DX12, I had FPS drop to 15 in main base, did a lot of terrain flattening.
instances are around 25300 there,
i didn't know that would be a culprit until i learned about it.
But now with Vulkan the FPS is between 50 and 75 in main base, i can live with that.

Anyhow, in other seeds i am keeping the instances as low as possible.
It's actually more beautiful when building a little farm on sloped terrain
within a big castle estate.

Game has never crashed so far... (knocks on Fine Wood for luck)