These are lots of different setups now tbh. I am working on 3 different Ubuntu machines simultaneously, 2 with 32 GB and one with 96. 2 different Kernels, all different CPUs and SSDs. Then you have different binaries too (release, debug, other flags). What I want to say that it's hard to tell from here which aspect leads to limiting RAM on your @otto machine. I also don't know anything about what will happen to mem usage/disk access in containers or VMs. I'd absolutely love to know more about it though 🙂
You can absolutely drop me a line to look into your issues and I'll have a look at it when possible.