Can I combine the zone number field in one column separated by commas and have only one listing for every door type?
No. The element scheduler is not capable of that - given the data fields you choose to display, it always displays either 1 line (record) for each element (door in this case) - or 1 line for all identical records. But, you cannot combine multiple fields (zones in this case) into one line that shows all values associated with something else.
You can put the door type as the first column and mark it as a 'headline'. Then, the door type will display once, followed by a list (one per line - sorted if you choose so) of zone numbers or names.
One of the forum moderators • AC 26 USA and earlier • macOS Ventura 13.2.1, iMac Pro 10-Core, Radeon Pro Vega 64