This type of plugg is a little bit more secure in regards to being accidentally pulled out. It clicks into place. My understanding is that a modem will draw the most current at boot-up. Working curent draw will be much lower than 4,3 A. An AliExp adapter will be adequate imo.
I tried an LPS on my modem with no success. Got higher latency and jitter and no improvement in SQ. I am now using the stock smps with an IFI DC-iPurifier2 whitch have improved SQ, latency and jitter in my streaming chaine. I think something like an IFI iPower Elite will be perfect to power a modem.
My wireless routers on the other hand profited on using LPS's. Go figure. Adding ground-boxes to modem and router also helps SQ ime.