I have a Front Runner Rack and took a moment to look at the Prinsu racks. The accessories are not likely compatiable. The Prinsu rails look to be minitex profiles which take a trapezoid shaped retainer and the front runner rack takes bolt heads and used the side rails to attach accessories.
Is the front runner a couple hundred dollars better? Probably.......
1, Experience tells me what we Put on the racks lchanges over the years or for each trip. The front runner racks have two mid rail bolt head slots that allow you to insert new hold down or new accessory holder without taking the rail out. The minitek rail seems to bolt in from the end and require retaining anchors to be inserted prior (think rattle) or removal of the rail (think pia) and inserting a threaded retainer required. That said the minitex is a proven versatile channel system.
2, There are many FR accessories that attach to the actual side rail which has its own retainer channels, again no removal. This doesn’t take up bolt on room on the top cross bars.
3, FR is always making new stuff that you might need and you already like their accessories
Note: One test I use is do I keep shopping for a rack after I buy one. I have not shopped after 4 years with a front runner rack.
I use RTT mounts, max trax mounts, highlift jack, rotopax mounts, rear awning, side awning and new this year under rack camp table. (not all at once)
Good luck