Although this creates extra work, it does reduce drag considerably. As the cars are so light, there is no detrimental effect on the life of the bearings.
The inner bearings’ inner seals and both the outer bearings’ seals must be carefully removed using a small screwdriver or other pointy tool.
You will also need to modify the dust caps on the outside of the hubs by drilling a Ø12mm filler hole in the centre of each and fitting them withtight fitting rubber grommets.
With the front hubs installed, remove each of the rubber grommets, and fill with 10WT gear oil until it reaches the level of the holes in the caps.
You should check the oil level periodically.