No, there is no annoying bits of Az-GTI (at least not I know about). I have taken a look at the source code of the Az-GTI driver, it is inherited from the EqMod driver. The only difference I see is that it defaults to network connections with the correct default UDP port and host IP.
So it is an EqMod driver. Which makes sense since the Az-GTI hardver officially has an equatorial configuration when one put it on a wedge (counter weights and everything). But what we are trying to achieve here (both me and JonCarleton) to use a big Dobsonian mount with Indi. This must be used in Alt-Az mode, putting it on a wedge is not an option.
In the beginning comment section skywathcerAPIMount.cpp it says:
* This file contains the implementation in C++ of a INDI telescope driver using the Skywatcher API.
* It is based on work from three sources.
* A C++ implementation of the API by Roger James.
* The indi_eqmod driver by Jean-Luc Geehalel.
* The synscanmount driver by Gerry Rozema.
So it is already based on the eqmod driver.
This driver is mostly works, with some annoying bits which I'm just trying to iron out through pull request to the indi github. But it is a slow process mostly because I myself have to became familiar with the quite complex Indi ecosystem. This is a huge peace of software!

Stash:
I appreciate your input and will look at the AZ-GTI driver before I commit to any code plan. I tend to look at as many options as I can and then start the process of elimination. What I have left on the table at the end is what I work with.

Sometimes that even works

Gupi: This is a huge peace of software!

The above is exactly why I appreciate the wisdom of this thread.

Alternative to waiting for Sky Watcher prodcuct and as long as you trust the pin outs (which are 99% ok) then you could just but a ready made EQMOD ( name is irrelant in this case it should work with anything) like this $12 inc del to USA www.aliexpress.com/i/32995620143.html

and just splice the mount end and put you own connector wired to the correct pin outs. The spec for EQMOD (e.g. AZEQ6GT) wiring is online on EQMOD so just a case of making sure you have connected to your new pin outs. Plus you of course can get the same cable in the USA

anyway I presume so only a couple of days waiting for delivery!

The SW product is, I am told, a Prolific Chip device where as the above is an FTDI which means no clash on USB ports (FTDI have a unique serial number) an in Linux Udev can be used to make that device a perm mount connection with appropriate name in /dev.

Prolific Chip devices are good too.

I've bought myself an USB-RS232 cable to update the firmware of the hand controller. The first one I bought was based on the Chinese CH340 chip, and it is very unreliable. In the middle of firmware upgrade just lost connection. I thought first I was managed to brick my hand controller. Fortunately the hand controller has some safety feature and recovered. I was never able to do anything useful with that cable (I bet the flow control is broken).
Later I bought an other one, based ont Prolific chip, and in works just fine!
Sometimes unfortunately one just cannot tell which chip a given product based on, just after buying and seeing the driver.

I have ordered both the FTDI/USB device recommended by Gubi and the cable recommended by Stash. Both come from overseas, so I don't expect them soon, but we'll see which arrives first and ultimately which works best. I have seen good and bad results with devices such as these, so I feel having a few different brands on hand will hedge my bet. If I just tried one method, and it was not reliable, I'd be out another month waiting for an alternative.

Right now, things from China are very unreliable. I have been waiting for a reticle lens from SVBONY for a couple of months now. Tracking says it is stuck in Singapore.

Anyway...will give me time to get my arms around the software.

FTDI is an American product as far as I know. You should be able to find a supplier in the USA, like Mauser Electronics.

Gubi: Your link sent me to a site which indicated a US option, but in communicating with the vendor, I found them to be in Taiwan. Not a big issue for me. I get a lot from that area...it takes a bit longer, but I've had good results overall.

By the way, mouser.com does have a USB->FTDI TTL 3.3V adapter cable in stock.

Scottish been around 20+yrs

Hmm. Mouser out of stock. That surprises me (from here I don't see Mouser US, the site drops me directly to Mouser EU...).
This is a quite commonly used item in microkontroller world.

No...you misunderstood. Mouser.com HAS them in stock. It is just that I already ordered.

I have forgotten to share the good news with you: we were managed to fix UDP connection in indi_skywatcherAltAzMount and indi_skywatcherAltAzSimple drivers. The patch has been merged into the github tree. I have no idea when will it get it's way into the precompiled packages, but it is not hard to compile the github tree, just follow the instructions in the main README.