For your Superbrush 24", the lighter gauge wire head is recommended for your use with 1/18" rift oak veneer and the delicate edges on your doors and panels. The lighter wire will effectively pull out the softwood grain without being too aggressive, which helps protect the veneer edges from splintering or damage. This aligns well with your desire to pre-brush the solid wood edges and minimize cleanup, allowing you to cut a 1/16" radius before running the doors through the machine for a clean finish.
Although a heavier gauge brush could yield a stronger texture, it risks being too harsh on the edges, especially if the feed rate and brush speed aren’t perfectly dialed in. Since you want to avoid pulling or splintering the wood, the lighter wire gives you better control with less risk of damaging the softwood or edges while still providing an attractive texture. If you adjust the brush speed and feed rate carefully, you might achieve some variation in texture but the lighter gauge remains safer for your precise needs.
Regarding your nylon brush, rewinding it is an option if you want a less aggressive finish after the wire brushing step. Your tests with the Makita tool suggest the nylon brush can provide a nice buffed finish without creating scratches or damage, which complements staining and dyeing before applying water-based poly. Overall, go with the lighter gauge wire head for delicate work on rift oak veneer edges with the Superbrush 24", and consider the nylon brush for finishing touchups.​​