our ILL team has asked for an add-on for OASIS, just like they have one for GOBI.

Would it be possible for the OASIS/ProQuest team to create an add-on to use with ILLiad?

Here’s the link to the main page explaining how to create and submit add-ons:
https://atlas-sys.atlassian.net/wiki/spaces/ILLiadAddons/pages/3149447/Submitting+Addons

What they suggest in the following link is to use an already created add-on and build on it. Since the add-on for GOBI already exists, the easiest would be for ProQuest to copy that add-on but use OASIS features instead of GOBI features. On the left-hand side of the page, you will see a main add-on directory, under which you will find an ILLiad add-on directory. In there, you will find the GOBI add-on.

I have also included a link to the GOBI add-on for easier access:
https://atlas-sys.atlassian.net/wiki/spaces/ILLiadAddons/pages/3149386/ILLiad+GOBI+Addon

There is also a ProQuest dissertation search add-on, which might help ProQuest programmers define how to build an add-on from a ProQuest standpoint.
https://atlas-sys.atlassian.net/wiki/spaces/ILLiadAddons/pages/3149451/ILLiad+Proquest+Dissertation+Search+Addon