In this case, I'll suggest you create a custom property of type "multiline txt" and create a contact-based workflow. Now add action to set a property and select this custom property and then use contact tokens just like I did in the screenshot below:
After running this workflow you'll see how this will set the custom property see below -
In this case, I'll suggest you create a custom property of type "multiline txt" and create a contact-based workflow. Now add action to set a property and select this custom property and then use contact tokens just like I did in the screenshot below:
After running this workflow you'll see how this will set the custom property see below -
Unfortunately twe can't merge system properties like this - these are required individually across assets in the portal and would cause many issues if merged into one. May I know the reason wahy you want to merge them