My KEF 105.4s have the original MFR casters, and I appreciate them when moving them.
I have wood floors in the listening room, spikes are out. If I do ball casters I will put them in "cups" when I position them.
I have no base on the woofer cabinets (W frame), I did extend the outer cabinet by 3/4" front & back to handle a grill cloth, however.
BTW, I would post more pictures, but nobody even commented on my "large woofer" in the last pictures, so I assume no one cares.