SCATECH EV1616DN - Example config

You're just making life hard for yourself if you want a reliable solution. But if you want to go down that path good luck.

Firstly I read this:
linuxcnc.org/docs/html/man/man9/hal_parport.9.html
Then read:
github.com/LinuxCNC/linuxcnc/blob/master...rivers/hal_parport.c

That should give you an insight into the hal parallel port driver works.

Now the task would be writing a realtime driver that mimics the functions of the haL-parport driver and talks to the the ethercat hardware. Once again the limiting factor will be the latency as this will affect the base thread period and the step speed.

Personally I think a Mesa card, 7i92 would be a simple upgrade to a 2 port parallel port system, is the way to go. This is the most mature & supported option.

There are also 2 really well supported & mature projects, Remora & Linuxcnc-RIO that can be used instead of want you want to do.

BTW I have created a couple of boards to use with an FPGA that can be used with Linuxcnc-RIO that will give you about 3x17 pin ports that can be used with a chinese breakout board, 1x12 pin port a 1x6 pin port and a 1x3 pin port.
This can also run modified Mesa 7c81 firmware to either connect to an RPi4/5 or (probably not of interest to you) to a PC via EPP interface.
I'm also toying with the idea of an Ethernet interface as well, but this is just in the "what if" stages.

Pardon my confusion.
There seem to be a lot of supported modules, I haven't looked at the capabilities of each one. What is the ethercat support for in Linuxcnc if not for IO?
Why would I need to write my own real time driver when the existing one is loaded real time? It seems to work.

I'm fine with creating my own HAL file . Where are the example configs? If I google linuxcnc 3 axis hal example, there are only people on this forum asking similar questions. The documentation only contains snippets. This is why I expected to start with my existing hal file created by stepconf

Sounds like you want to use this IO board to drive Step/dir signals for a stepper motor driver.
It will work kind of but you will be severly restricted by the slow speed of the servo thread. 
Say 1 ms servo thread, which is normal, and you will get max 500 steps per second. You will need 10 times more than that, easily.

Ethercat will work with Ethercat servo\stepper drives and other Ethercat devices, unfortunately my endeavors and experiments have been in other areas.

Linuxcnc comes with a plethora and sample & simulation configs, but what you want to do may not be even possible or may require more work than you've assumed. Have you explored the Linuxcnc menus, tried a simulation config, read the Linuxcnc docs ?
Did you even bother to have a look at the 2 links I gave you ? One of them explains the reset function.
When you try to run a config that you think will work what errors if any are you gettting ?
Are you getting any output at all ?
Have you got access to a logic analyser or 'scope ?

Does Ethercat hardware support updates every 25000ns, as this would have to match the base thread timing. Otherwise the steppers are going to be very very slow with updates every 1ms.

The best bet would be just to get a single axis moving, as a proof of concept and evaluate the performance.

There is a lot that you may have assumed & expected that may not be the case or possible.
Tho it does sound like a reasonable & unique idea, but I think you may be delving into unknown territory. So you make have to come up with a lot of solutions on your own.
No one would try and shut you down, but there maybe more hurdles than you realise.
In honesty I don't see how it would be an improvement over an external board that generates step & direction timings. Or an ethercat driver servo/stepper driver.

Assuming the Mesa 7i92 is my answer, I'm in Australia, I looked for a local distributor and a 10 year old post on CNCZone from rodw said that he too was Australian and had them for sale?? Is this still the case and how do I go about buying one?

Yeah I'm no too sure about that.

Where abouts in Oz are ya.