Webform and Soft Credits
we did merge a PR fairly recently re: soft credits; I tested it extensively and it is working fine - try upgrading to the latest -dev version [best to do that on a test site - though I have some production sites running -dev at the moment]. Let us know!

PR: https://github.com/colemanw/webform_civicrm/pull/68

Awesome - one webform -> four memberships - paid for by parent -> in four installments. That soft credits PR was a first pass at that functionality. I'm not surprised not all of these situations are accounted for (yet).