The selvedges on my twills seem to have a ridge instead of laying flat like a plain weave selvedge. Can I do something different with the threading on the edges so this doesn't happen? Is there some other way to make sure the selvedges stay flat?
Are you pulling in your weft too much, after including your floating selvedge, when you throw your pick?
Also, have you seen this article on the Knowledge Base? It might be of help - https://janestaffordtextiles.com/knowledge-base/in-praise-of-good-selvedges/