"The concept of the silly triangular net with the piffly draw string across the front went out amongst thinking anglers 20 years ago...."
Maybe I'm not a thinking angler then.
I prefer a triangular net for bait fishing. From the bank, it's hard to net a fish in shallow margins with a round net as you can't always get right under it.
I've tried the round nets with "lure mesh" and found other problems, even when boat fishing.
If I need to net a fish off the boat bait fishing, I find I can pull the net in to the boat, unclip the trace and the fish will usually sit quietly.
I can unhook most over the side, again they're only lifted out if I fancy weighing or photographing them, which is rare.
Fish are easy to net in a round net from the boat, but because they haven't usually got the "spread", ie a small diameter, the fish is scooped up and it falls into the net, with the mesh engulfing it as you lift it out.
This often means the fish thrashes about like f@ck and has to be lifted into the boat to be unhooked.
Two sides to everything, especially if you mostly bank or bait fish.
If you lure fish most of the time you need the right mesh if there's any chance of getting a bigger fish, unless you tend to use lures with just one or two hooks where you can chin most in safely and net the odd bigger one without too much drama.
If you want just the bits, Northwestern used to sell arms, draw cords, blocks etc separately.