Just realised you were first to suggest using a wired router only, and offboarding a separate wi-fi router if required. Even before @sns suggested it !!
But regarding LPS, I always championed them and found they improved everything non network, but when it comes to switches and routers sometimes its the reverse and the stock SMPS is better.
Maybe I just do not have enough LPS on hand to find the correct one for network gear. In the meantime I found the iFi X and iFi Elite SMPS power supplies work great with network hardware, a step above stock SMPS.