My editing mistakes
If you need to add numbered etymologies, it's ok to leave them empty, but if there are no numbers it's probably best not to include it at all. Alternatively you can add {{rfinfl|lang=de}} to add a notice that it needs an etymology.
Of course you meant {{rfe}? The one you've posted is for inflection. I think I'll be using numbered "Etymology" headers, and put requests for etymologies under it. That seems the best looking option. I bet I won't be using it much anyway, there aren't that much words in German that would require doing it. Anyway, thank you for your time. You've helped me a lot.
Oops, yes! Don't add requests for etymology in inflected forms like Tees though. Normally, the etymology of inflected forms is the same as their definition, more or less, so there's no way to say for every plural how it was formed from the singular.