[Enhancement] Statusline modifier for alignment

I would like a function that I could drop into my statusline to align my statusline text with the goyo margins. Is this possible? I don't know much about vimscripting so I don't know if statusline functions can be added by plugins. If it's easy to implement I would greatly appreciate it.

The issue names no files or tests. Start by locating the plugin's Goyo margin handling and any statusline-related entry points, then determine whether a Vimscript statusline function can use those margins. Done means a documented modifier can align statusline text with the active Goyo margins, with behavior verified in Vim.

Written by the indexing model from the issue text.