Adding a feature to the acronym package

Question

I am trying to add four specific features to the acronym package and plug it into Overleaf:

1. \acrounlisted - creates an unlisted acronym, which would be treated like an acronym (in that the first time it's used it would define it and then just use the acronym after that), but it wouldn't appear in the List of Acronyms.
2. \acfirstuc - Makes the first word in the definition uppercase iff it has not yet be used--otherwise, it's just \ac.
3. \acalluc - Makes each word in the full definition upper case (e.g., if \ac{ods} expands to "oxide dispersion strengthened (ODS)", then \acalluc would expand to "Oxide Dispersion Strengthened (ODS)").
4. \aclc - Makes each word in the full definition lower case (e.g., if \ac{ods} expands to "Oxide Dispersion Strengthened (ODS)", then \aclc{ods} would be "oxide dispersion strengthened (ods)").

I have specific reasons for this in my thesis. I realize that unlisted would cause some problems with the link that is generated to between the acronym and the list of acronyms, so that should probably be stripped out, too.

The problem is that I'm a little bit new to LaTeX, and anything I try irreparably breaks the package. I'm using the acronym.sty file from the TDS archive on CTAN, and using \RequirePackage{} to bring in a renamed version of the .sty into my project's class file. I was trying to use \lowercase and \capitalizewords from mfirstuc. I don't know how to just capitalize the very first letter (and if it's terribly difficult, I will leave that one off), or how to properly implement these.

Is anybody willing to take a look and give me some pointers on how to modify this thing?