I think it’d be cool if there was a maintenance table item that, when placed affixed to a foundation or foundation-connected item, figures out the repair costs of everything connected to the foundation, and lets you pay for it right there in the table. Additionally, it’d give you the ability to pay in advance to keep the repairs paid for up to two weeks. With this item, it wouldn’t be necessary to do the floor-by-floor decay thing, so people wouldn’t feel the need to build crazy towers to work around it.
Another cool idea would be a clipboard that you can right click on a door or spike wall or gate/gateway to consume a sheet of paper and load the item into the cllipboard. Then you could take the clipboard to the maintenance table and load non-foundation-connected items into the maintenance table to repair and prepay them there too. This would make it easier to manage spikewalls which are going to be out of control with regard to repair, I can tell.