Lansweeper scans and stores a huge amount of data from network assets. Things like error events, last logged on user, toner status or page count on printers likely change with every scan.
The "last seen" date refers to the last date when an asset successfully has been scanned, no matter if anything has changed on it or not.
Nearly every table in the Lansweeper database has a "lastchanged" column. This is the date when information in this table was added or updated. You might be able to select tables which are relevant for your purpose. If in your CMDB the last logged on user is important, you could use
tblCPlogoninfo.logontime as filter for the import. For other purposes you can use the "lastchanged" field of other tables.
Note:
tblAssets.LastSaved does not always get updated if any change has been made to an asset. We recommend not using this field for your purpose.