You can now sort the term-translation pairs in the language pages in alphabetical and reverse alphabetical order of the terms.
https://poeditor.com/kb/how-to-filter-strings-localization-project

I would also welcome to sort the terms alphabetically, duplicates ma be sorted by context.

The "original order" is just confusing if you add terms manually.

Could we have a sorting option that match something that can match msgmerge?

https://www.gnu.org/software/gettext/manual/html_node/msgmerge-Invocation.html

Any sorting order that we can replicate on the other end would be an improvement, as we're currently getting huge diffs when syncing with github :(

We need some way to manage the order of terms. There are proposals for Drag & Drop reordering, Using the order from the file when importing terms, and this one.

I'd be happy with any of the solutions, but I think just having an option to always sort terms alphabetically is easiest in terms of implementation for you. It could also be just a button to "sort terms alphabetically".