OP wrote:
"I guess my intentions are to run the system via my iPad Pro or iPhone 14 with a suitably good app."
Well, in that case, you should consider what is absolutely
the best "app" out there:
The
FREE Roco z21 app.
You can try this right now "in demo mode".
Go to Apple's App Store
Search for "roco z21".
There are actually TWO z21 apps:
a. older one (red engine on a blue background)
b. newer one ("Z21" in white on charcoal background).
Download either or both.
Did I mention above that both are absolutely free?
You can run these "in demo mode" to see how everything works.
Of course, to actually run a train on the layout, you'll need a "hardware box".
Also, since you have an iPad, you can run TWO control cabs side-by-side with the iPad in horizontal orientation. I do this myself (but with an Android tablet). Download the z21 app, and try it in demo mode to see for yourself.
There are a couple of Roco hardware units.
The first is the black Z21. You probably don't want this -- too expensive (although there's currently a used one on ebay for $325).
The second is the white z21. It doesn't have all the ports and pizazz that the black one has, but it's "good enough for the rest of us". I have one myself.
Unfortunately, the white box version is hard to find -- you'll have to buy it from Europe, as I did with mine.
A possible source, for both the z21start (white box) AND the companion wifi modem which gives you wifi with it:
Abwärts kompatibel zu allen MultiMaus-Modellen und zur Lokmaus 2 über den X-Bus Anschluss. Diese bietet auch das ultimative Fahrerlebnis mit fotorealistischen Führerständen. Zusätzlich ermöglicht es die Verwendung der z21 MultiMaus (Art. ).
www.ebay.com
The shipping is a little high, but again, consider it as a package price, this will do what you need.
The only other thing you'll need is a cheap "converter plug" to adapt the Euro-style power block to USA style.
(The power block should work on both voltages)
Again, if you really want to run from the iPhone or iPad, the z21 app is what you're looking for.
It works fine with JMRI, too.
In fact, you can have JMRI up-and-running with the z21 hardware, and use both the iPad AND the iPhone with the z21 app, all at once.
(Also, the z21 app will work with the Digikeijs DR5000 and YaMoRC hardware controllers, but these are unavailable right now.)