Here is a little Blender Python script to round vertices positions from something like 1.0001 to 1.0.

It operates only on the verts you have selected while in Edit mode. If you want it to run on all verts then comment out lines 7 and 8.

import bpy, bmesh
from mathutils import Vector

bm = bmesh.from_edit_mesh(bpy.context.edit_object.data)

for v in bm.verts:
    if not v.select:
        continue
    
    for part in range(3):
        rounded = round(v.co[part])
        diffFromZero = v.co[part] - rounded
        
        if (diffFromZero > 0 and diffFromZero < 0.1) or (diffFromZero < 0 and diffFromZero > -0.1):
            print(f"Before: {v.co}")
            posMove = Vector((0,0,0))
            posMove[part] = diffFromZero * -1
            
            bmesh.ops.translate(bm, verts=[v], vec=posMove)
            
            print(f"After: {v.co}")

    bm.normal_update()
    bmesh.update_edit_mesh(bpy.context.edit_object.data)

Enjoy!