讨论下preferredMaxLayoutWidth

这个框架我用很久了，感觉一直没解决多行label要设置preferredMaxLayoutWidth的问题啊？，我看中文博客说解决了，我在使用的过程中一直要自己设置preferredMaxLayoutWidth。是我的使用姿势问题，还是的确没解决？

Start by reproducing the multi-line label case described in the issue and inspect how the framework handles preferredMaxLayoutWidth during automatic cell-height calculation. Determine whether the behavior comes from usage or an unresolved framework limitation, then document the conclusion and any affected entry point.

Written by the indexing model from the issue text.