MS word has this option to cycle a highlighted word/s through full/no/first capital letters using Shift+F3. Please add it to Onlyoffice.
Hi @PaTa 
Thank you for your suggestion!
We already have a similar feature request regarding the ability to cycle through full, no, or first capital letters (like the Shift+F3 option in MS Word).
I will add you to the request list for this feature. Unfortunately, we don’t have an estimated timeline for its implementation at the moment.
We will keep you updated on any progress!