A long time ago I used to keep all the type editable in my designs. I stopped doing that after several years on the job. For most
sign designs I convert the text to outlines once the design is finalized. The project's spec sheet will contain a listing of which specific fonts were used. That's it.
The only time I'm going to keep the text editable if there is a lot of it. But even then, I'm going to have two versions of that finished file, one with the editable text and the other with it converted. Or maybe I'll keep a copy of all that text in a Notepad document.
There's all kinds of problems involved with keeping lettering as editable text objects.
Obviously you need the fonts that were used in the design installed on your
computer. Not just that, but I mean the very same font files that were used. There's a lot of different flavors of the same typeface floating around and they don't all have the same geometry and metrics. Times New Roman on a new
Windows 10 machine is not the same as Times New Roman on an old
Windows XP box.
Lots of font files are not cross platform compatible. OpenType, when done right, is the only format that truly works reliably. TrueType works most of the time, but the ones from a Mac often won't work on a PC.
Some font formats, like Type 1 Multiple Master, are now dead. Even if you have a copy of FontLab Studio there's no guarantee you'll be able to open and save a "single master instance" version of that font that will work properly as a substitute in old artwork that used Type 1 MM fonts. Back in the 1990's our shop used CASmate and a bunch of those proprietary .SCF fonts. A lot of those did not get ported over to TTF format when Scanvec and Amiable Technologies merged. I have some old .SCV files from the 1990's that are mostly broken because of that. The files will open in Flexi, but they'll be screwed up with font substitution errors.
And then there's the freaking design programs themselves. Current versions of CorelDRAW, Illustrator and Flexi DO NOT handle type the way they did several versions ago. Text elements will flow differently. Effects like text on path can yield some very unpredictable, very unreliable results.
Lately we have a new problem with developers removing compatibility with old software. My personal copy of CorelDRAW X8 won't open CorelDRAW 3 files. Adobe killed Freehand after the Macromedia acquisition and then removed Freehand import capability in Illustrator recently.