Improving deployment process of agent software
ansible-pull would work well for this, though it makes the assumption that your clients are using ansible. That's not an assumption I would be comfortable making in your shoes.

At this point it would appear to me that developing our own script to further automate the process would be a better solution

I agree with that. Since you already have a script to figure out what needs to be downloaded, I'd extend that script to download the needed file(s) and trigger the installation/registration.