@swsswr Lansweeper licenses are based on the number of scanned assets, not on the number of scan servers.
Indeed, with the proposed setup, the information from each air-gapped network will be separated from your main Lansweeper installation. Since those installations will not have internet access, there will be some discovery API errors. That API is used for extended display scanning and credential-free recognition, but if you don't need those features, it should not be a showstopper.
~~~~~~~ (〃 ̄︶ ̄)人( ̄︶ ̄〃) ~~~~~~~
Sweep that LAN, sweep it!