Yes, there is another solution. Although, necessarily not one that is easier... But if you for all instances set up proper certificates and then make sure that the certificates are trusted on the machine(s) where you run the PowerShell scripts. They would be trusted if they come from an external provider like VeriSign. You can also use self-signed certificates - cheaper! - but then you need to copy these to the local certificate store on the client machines.
This is a lot better than using Trust Server Certificate, since with the you accept to be victim to a man-in-the-middle attack.
Then again, if you have these PowerShell scripts well assembled, it should be too much work with a good text editor to run a find/replace to add the argument for TrustServerCertificate...