Hi @RBakker86 and thank you for sharing your feedback and outlining your team’s requirements for individual signatures in HubSpot Help Desk.
I can see how important it is for your organization to reflect personalized details.
I’ve noticed a similar idea already present in our Ideas Forum: “Improved customisation of helpdesk email signatures (more personalisation tokens)”.
To contribute, you can upvote the existing idea and share more details about your specific use case in the comments.
I have added my upvote 
Also, as a reminder, there is the workaround from @CTalavera on this thread where they mention you could use snippets in the meanwhile. I understand this is not exactly what you are looking for but I hope it helps in some way.
Have a great day!
Bérangère