If you have version 1.3a then you already have this:
From the help
Force all Gcodes on for Marlin

FALSE (default) = use optimized Gcode output that does not repeat G commands if they are not needed
TRUE = force output of G code on all lines, useful for Marlin firmware that requires this.​

This item can be found on the Feature Options menu, if you don't know where that is, RTFM!
hit the

in the toolbar (1)

I don't fully understand this statement. axis words are always output in that order.

If you mean that every line must have every axis word, ie all of X Y and Z words, then:
a) upgrade your controlle seriously, being restricted like this means your controller is very old and you will be much happier with a new one since any 'modern' Gcode generator will generate optimized code that will be a problem to your controller.
b) hire a programmer to write a post processor for you, that will take *any* Gcode format as input and output it in a format that your controller likes.

c) you will have to delve into PhlatMill.rb and do some editing

you will need to find *all* lines like
if (xo != @cx)
and change them to
if ((xo != @cx) || @axisoverride)
and similar for 'yo' and for 'zo'.
Then add
@axisoverride = true
at the top of the file among the other preset globals like @debug

This will force output on for all axis words even when the current position has not changed.
(and you will have to do this every time you update SketchUcam, and yes, a new version is about 2 weeks away)
Leaving out axis words, and also G words when the new line is doing the same move like G01, originated with paper tape readers and limited memory in the controllers. To save paper and memory, G01 and G00 (and others) are 'modal', once set, they stay in effect as the current 'mode' until changed by a new code. This is part of the Gcode language specification and a controller that does not support it is 'broken'.

BTW, upgrading your machine will probably have the side benefit of it running faster.
Running faster = more parts per hour = more money

(1) a general note on help systems. The help that comes with your software is seldom perfect. However, it did take a programmer HOURS to write it, and programmers hate writing help, we would rather be programming!
So, everyone, please read the help, it really will help you!

 

well, reading the help would have been faster, that feature is mentioned on the front page in the release notes (-:
a few clicks and you would have been producing code!
If I had gone flying this morning you would have waited another 12 hours! >-:

I have added about 11 things for the next version and need to write help for all of it..... so maybe I am a little touchy about help right now LOL

it does that on purpose, you want to retract Z before moving X and Y to 0 so you do not crash into anything.

have you looked at FreeDOS? it is a relatively modern replacement for MSDOS and will run on new motherboards.

and, you do not need to have a specific machine for it, you can run it in a virtual machine (like Microsoft Virtual machine) on your normal Windows desktop. The virtual machine is just a file on the harddrive and can be backed up along with all your other files so if the hardware dies you can just load it on a new computer.

ah, ok, so running in a virtual machine will not work. Well, you should be able to get a new PC working with FreeDOS, and with some hassle with Windows, even dual boot it.

have you looked at Vectric Vcarve Pro? and also Fusion 360. Fusion 360 is impressive, search youtube for NYC CNC and watch his videos about it. and you can try it for free for at least 30 days. Vcarve Pro is more geared toward doing flat panels and is probably even better for that machine.

Although the new version of SketchUcam I am working on will be able to do toolchanges, I really think you need software that is geared toward multiaxis machines like that one, both for safety and for productivity.

thank you (-: