This makes handling gases within vats incredibly difficult without creating mixtures.

For reference, I pulled about 800,000mb of nitrogen and oxygen out of a decently small vat before a full vacuum was pulled

Full vacuums are indeed very difficult to create in a real lab. There isn't any real need for a full vacuum, so this won't be changed.

Try using Mekanism. It will make vacuuming a Vat much easier.

Let me also state that this was because when getting to very low pressures, it would randomly consider it to have more in than it did and jump between 0.001 moles and well over 1000+ and would sometimes make it impossible without breaking the vat and attempting to do it again

just realised I forgot to say this

This is the same issue as #184 was having, I just forgot to state this was the reason for having to pull so much gas out.