It really depends on your body, some get sick just from the smooth locomotion mode, some can fly jets in VR.

I haven’t tried too many mods in VR Minecraft so I can’t really tell.

Personally I don’t have motion sickness as long as my horizon matches my standing/sitting position. A friend of mine took me for a helicopter flight in VR Gmod, as soon as they took off I had to take off my headset, guess it was the horizon misallignment which triggered dizzyness. For comparison I can drive cars in DiRT Rally and Beam.NG just fine as there horizon by default stays flat/doesn’t get rotated.