All of this is absolutely true, Jude. Playing Techniques can now have continuation and transition lines. See pages 47-50 of the Version History
You are right, but you can’t still have full flexibility in formating them (for example you can only have fixed thin and thick lines). You can’t neither make them completely vertical. If you need to use straight lines in a more flexible way, you can use modified slurs as I show in this video:
