I'm a bit confused after reading this. Is the issue that you want to be able to gather information on devices that are both:
*Not Windows
*Not on your trusted network
If so it can't be done with the current built in feature-set, and at least from my perspective would probably require a major overhaul of the product.
Lansweeper is a query based tool, always initiated from either an agent, or a server/device which kicks off specific actions. Something needs to exist within a particular segment to tell it what to look for, and where it can put it when it is done. The big difference with something such as Splunk is that logs are constantly being generated, and you know you want them, so it is perfectly fine sending them along to whatever collector you have in place without anything else getting in between. Lansweeper needs direction. The gap that needs to be filled by Lansweeper to make something like this possible is a scan/aggregation service that can be deployed in a lightweight fashion without a database requirement that can package and deploy information to their Cloud Gateway, eventually sending it to your local instance to be imported. I can think of so many ways for this not to work though unless you do have some sort of remote manageability available to you... Credentials? Configuration?
Sorry, I went off on a bit of a tangent. It just got more interesting as I was thinking about it.