Engine Controls

I take your word on SFs, because in my neck of the woods there aren't many around.
But I did come across several Kobelt controls in fast MYs (both OEM installed and retrofitted), obviously also in the f/b, hence much more exposed to weather than in the main helm.
Some of them were 20+ years old, and the worst I've seen happening to them is that the control head at the base of the levers loses its shine and looks worn out, in the chromed version (as opposed to the more durable black version).
BTW, Kobelt controls can also be interfaced with their own wired remote, which is somewhat ugly but very solid, and allows full control of everything: gear/throttle/rudder/thruster.
Which for all intent and purpose, can also replace a fixed third station.

At risk of stating the obvious, another thing to consider is that with electronic controls you lose the separate levers for gear and throttle.
Which many folks hate, but most of those used to them (myself included) prefer them to single levers every day of the week and twice on Sunday!

I can neither confirm nor deny what you remember, but my (possibly outdated by now!) understanding is that the only producers of electronic controls with separate levers used to be Livorsi and FB Design of Buzzi fame.
Unsurprisingly, because for "normal" boats like those we are debating, single vs. separate levers is essentially a matter of preference.
But with ultra-fast boat meant to withstand wave jumping, separate levers are an absolute must.

Single levers are much easier and free up your hand for bow thruster controls or other measures like steering in tight spaces. Seperate levers for race boats are one thing, but everything else the single levers are much easier, also keep certain people from shifting with the throttles up and damaging gears and running gear.

Whatever happened to the old Morse KE5s? I had them on a 70 with 3412Es and they were pretty good.

I never, ever had to use the throttle levers while maneuvering, because engaging/disengaging gear is more than enough, unless you like to dock Chesapeake cowboys' style.
Which means that the only handling difference is that with separate levers you don't need to worry about accidentally accelerating when engaging gear.

I can't recall if this is also true of the Hynautic system which is being discussed, but just as an example, mechanical cable levers like these incorporate a safety lock that don't allow you to do that.

All that said, what part of my previous statement "single vs. separate levers is essentially a matter of preference" you didn't understand?

Re. Use of throttles.

It depends on the boat and the size of the engines. Trawlers or underpowered boats will need additional RPMs when maneuvering. Planning hulls with larger engines usually don’t but sometimes bumping to 1000 can come in handy. Same with rudders, I know many advocate not using rudders but it can help as well.

All agreed.
When I previously said I never touch the throttles while maneuvering, I was referring to my current planning boat, which makes 6+ kts at idle and reacts to gear engagement alone even more than I'd like.
In fact, coming from a trawler that I owned for 17 years, it took me a while to get used to her.
OTOH, also with the trawler I rarely used the throttle levers when docking: I only had to with crosswind, also because she had no b/t.
But other than that, it was mostly a matter of keeping the gear(s) engaged for much longer than with planning boats.
By and large, with the trawler I had one or both gear engaged for about 80% of the total time it takes to dock, while with my current boat it's the other way round: after a brief gear engagement, the boat gains enough inertia to move fast enough in neutral, requiring only a final gear touch to stop her.
I'm referring to mooring stern to dock BTW, which is what almost every marina requires, in the Med. But the principle still stands.