Well, you could leave the Wifi clients going and not set up the SSIDs on the router until the testing is over then set up SSIDS and PWs as a simple solution to that sir.
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Overall the process should be followed and allow the router to fully setup. Yes I can understand the frustration that it should just work however given the new processes for SB and the improvements Iv'e seen, it's working much better than before and given this process I found, it allows the router to set up SB values and settle in. Since doing this process, my router has been stable and working great for me and others. I'm actually more satisfied now with it and happy that it's reached this point. Yes I agree that it's not been as we had hoped since it's release however it's come a long ways now and it working well.
I believe there are still limits on the reservation side however I haven't had a chance to test that since I don't think I have that many. Maybe you can test this. I know I always recommend reserving IP addresses for ALL devcies however when it comes to these home class routers with this limiation and users having more than 25 devices, I recommend that users off load the reservations and convert the non priority or lower used devcies to Static IPs, devcies like, printers, NAS, controllers, cell phones, Pads, wired APs or any PC that doesn't need a whole lot of bandwidth or router mangement. Set ALL off those or as many of those devcies to static. This will help in gain some Reservation space for those devices that need bandwidth and router management and SB. Set the Static IP devcies out side of the DCHP pool range, 192.168.0.2 thru .99 or .200 thru .254. Leaving the default DHCP pool range for Reservations.
Give the suggestion and process a try, I think you'll find that your router will become more stable. Yes it's takes a bit longer to do it this way however the router is working well after using this process.