Your client will remain connected and in sync with Xero unless you tell Dext Precision otherwise. Disconnecting a client from Xero will mean that the client will remain in Dext Precision in its current state – it will no longer receive updates from Xero. You can do this via the Unlink from Xero button on the Client Overview page.
If a client is not connected to Xero this will be indicated by the open padlock and the Link to Xero button. If you wish to link a client back up with Xero, clicking this will redirect you to Xero for re-authentication. Dext Precision will do a sync after re-linking, so that it is up to date with any changes.
Xero also provide a way of removing connected apps directly from their site.
Even if disconnected, your client’s data will remain in Dext Precision until the client is deleted.