As long as you can create an icc in your other software you have all you need to build a full media profile in Onyx (assuming you don’t have Ripcentre)
“create” a new Media in Media Manager - give it a name & select the dpi you want to profile by highlighting it on the list to the left.
Then begin to add your calibrations.
Start with the ink restriction - print the swatch & restrict the pure colours where you can’t see or measure any more significant change in density and enter the numbers.
Next do a linearization - print & read with the eye 1.
Then print & assess the ink limit - judge by eye where the black shows no bleeding or artifacting - if you need to cut back into the colours it’s OK but you may limit your gamut.
The last step is to print & read the icc swatch but you can’t do this with your version so you will need to import one built with your Gmac software.
The icc profile is simply a table of figures which represents the difference between the colours your setup produces and the colours that the icc standard requires.
Thus in theory I suppose a “do nothing profile” would have all the figures set to “0”.
I’m guessing this would mean the software assumes your output already matches the icc standard exactly and would not make any changes giving you the same output as if you were not using a profile at all.
When you read the patches you may be given an opportunity to manually change the data - set everything to “0”
I have no idea if this will work - that’s all I can think of!