A someone with two middle names "only" totaling 19 characters I still run into issues with many forms, both online and offline.

I'm never quite sure what to do on offline forms that have boxes for characters that run out, I normally just continue writing past the boxes, but at least one official government documentation has been addressed to me just missing the second one.

And a few things seem to handle having multiple middle names (and thus middle initials) poorly, ignoring the length.