As ive already said, if you want to fit the top spring seat of the coilovers which is about 1 inch diameter = ie all of the cars weight concentrated on approx 1 sqr inch which then fits on the inside radius of the bearing where none of the actual bearings are then go for it.
All your doing is placing the cars weight not on the bearing area where it is with the stock OEM spring cups,
Hence using the large washer which is spot riveted to the OEM spring cup and thereby dissipating the load over a larger contact area and over the actual bearings which are on the outer radius of the top mount bearing not the inner radius where the Raceland upper spring seat will otherwise sit.
If you were fitting the coilovers with new pillow ball mounts then fine, they are designed to be used with 2.25" coilovers, the renault ones are meant to have the large washer/collar fitted underneath the bearing between bearing and spring seat hence me using it...