Will do! Thanks again!
Enjoy your time off!! 
As for the HTTPS: Letsencrypt won’t issue a cert for my DynDNS domain, since too many certs have been issued for it. And no, not my personal part of the domain, but the base (ignorelist.com).
So using the automated LetsEncrypt part of FritzOS 7 and having to use the myfritz domain name will make it look ugly, yet be a fire&forget approach to the problem.
Sure, you can still use a self generated SSL cert on the Nextcloud box (or even buy one), especially when you are the only person accessing the site.
usually this should be solved while trying to apply for a certificate by the beginning of a week (and pls take into consideration that weeks in the US usually start with sundays)
Well @buckesfeld is referring to the Let’s Encrypt limits and in this case the limit for Certificates per Registered Domain, which is 20 per week. With dyndns.com for example, only 20 certificates (simplified 20 users, when each user only requests one cert) can be requested per week. With thousands of users that limit could easily be reached.
However, Let’s Encrypt is actually taking care of this problem and every dyn dns provider can request to be added to a list. This list is taken into account in regards to the cert request limitation. And so there is no such limitation for the domain of that dyn dns provider - as long as he writes himself to the list.
Details can be found here:
And obviously, myfritz.org would have the same issue. That’s why I don’t see an issue with DynDNS for your own server and Let’s Encrypt in general. It is not necessarily related. You only need to find a provider that fits to your needs. Additionally, there is always the option to buy/ rent your own domain. No ugly names and no issues at all 
Perhaps an other solution, while Provider-(Cable)boxes are often ugly branded.
Use only the provider-modem, which is normaly free of charge. Then connect the modem-port with the LAN1-Port at an free purchaised fritzbox. Now you can route/forward the ports (IPv4) you want.
I drive my own nextcloud via a fritzbox 7590 and the Provider is 1&1 (DSL-50). It runs on an Zotac-Zbox with Windows 7 as the host and a virtual Machine (VMware) with Linux-Mint as the guest; because Nextcloud runs only on Linux.
For the DNS-Update, the Domain itself an the SSL-Certificate I use dynu.
Have a try: https://termitencloud.net
More over, feel free to contact me on ebertus@posteo.net
Greetings