Sorry about your issue, neighbor disputes are the worst. Just brainstorming here:
Do you have all the info regarding easements between the 2 properties? Any easement that allows each other necessary access to repair/maintain things like shared sewer lines? Utility easements granted to the utility companies won’t help.
Even if there isn’t one in writing, you can make a reasonable argument that one exists since actions taken on his property have caused damage to your property, via the sewer line. Since he refuses to take action, it’s necessary or implied that you may take reasonable steps on his property to protect yours.
It appears he feels he has an easement to your property to perform work that benefits his.
Lis Pendens (Notice of Pendency of Action) are a cloud on Title. No Court permission is needed to file one against his property. Nearly impossible to sell a house with that. Financing would be problematic.
But I think you should at least talk to an attorney about it. I’m not sure if a Plaintiff can file a motion to have the Small Claims case transferred to the main Superior Court, but it’s worth a shot. And I believe you can always file an Amended Complaint in the higher jurisdiction, with the easement claim which will satisfy the property rights claim needed to support a Lis Pendens.
There can be risks with that approach. But if this is as big an issue as it appears, it could be worth it. If nothing else, the military member with new orders will need to hire a lawyer and start the litigation process. In the meantime his house won’t sell as long as the Lis Pendens is filed. And I’m assuming the current state of how rapidly Court hearings are set is not that swift.
You have all the leverage. Assuming he hires a common sense attorney that lets him know life is too short and it’s in his financial best interest to agree with your terms and save himself a pile of money and headache. Or he hires one that milks him for all he can during these uncertain times.
In other words, you should’ve taken Hobies advice.
Edit: Just saw your update. Him having his transfer orders cancelled is odd timing. Hopefully you don’t get blamed for that.