A glance at my software downloads page will tell you that it wasn't just Giocoso which had lately developed a problem with accented characters on Manjaro+KDE. In fact, every piece of software I've written which uses the metaflac utility to read FLAC metadata tags suffered from the same problem. Accordingly, all needed to be fixed and all now have been fixed; each utility can therefore be updated whenever you're ready, using the utility name plus the --checkver run-time switch.
In other words, if you wanted to bump AES to its latest version, you'd type aes --checkver. If you needed to upgrade Niente, it would be niente --checkver. And so on.
A reminder that if you are not running Manjaro+KDE, it is quite possible your accented characters are working just fine in all of these utilities, and thus the upgrade is not essential. Kubuntu, for example, is Ubuntu+KDE and has no accented characters problem in any of my software utilities. It is only in Manjaro+KDE that the system locale seems to get mis-configured to the point where metaflac starts to auto-convert to unaccented English characters when confronted with European characters using proper diacritics.
Every upgraded utility can have the use of accented characters forced at run-time and on a one-by-one basis by supplying the --accents switch every time the utility is run. But since there are ten or so utilities this can apply to, a possibly simpler solution is to set the environment variable GIO_ACCENTS=1 in your .bashrc (or equivalent environment-setting file, such as /etc/profile, .bash_profile and so on, depending on your distro). If that environment parameter is set once, then all utilities will pick up on it and apply the "don't convert accented characters to English equivalents" behaviour in response.
Again, though, if you aren't already suffering problems with accented characters being auto-translated, there is no need to set this environment variable, since you have no need to apply the 'fix' the software updates bring in the first place. Manjaro+KDE users may well wish to upgrade swifly, however!