By filtering the List of Assets action using the current IP item in the loop, you can avoid the second Loop and the branch action. If you want to reference a previous step in your filter, remember to change the Filters field to "Template" (the grey icon at the left of the field) and click on the + icon to add your reference.

This workflow does not consider duplicates. So if you have 2 assets with the same IP, only the first one will be edited. If you want to edit all the assets with the same IP, then you still need to add a second Loop, but in this case, it won't loop over all the List of assets, only the assets with that IP.
In the upcoming release, we’re introducing a new action called "Match Assets". This action lets you quickly match a list of external assets against your Lansweeper assets and instantly see which ones match or don’t. This makes the process even simpler than before. Stay tuned!