I agree in some respects, but the main issue here is that fundamental tools that are available in the CK and which are a pre-requisite for any worldspace making are bugged or not working full stop. The very least we could have and should have expected was to be able to do all that we could with the CS and then a bit more. What we have got is non functionality with stuff we could do with the CS (in some cases) and stuff that in some cases is good and nice, and in others a complete waste of time.
As for beta testing, there is no way that beta testers can possibly be blamed for anything, that they did it at all is credit to them, but the question must then be asked, why did Bethesda not find from the community a few modders who worked on landmasses and ask them to beta test functionality regarding what is important to some segments of the modding community.
Cheer up!
Assuming the latest TESAnnwyn version works fine, you can create a brand new esp from scratch with a full landmass that can be as much as 4 times bigger than the restraining 1024x1024, hey, you've made Mesogea!!!
So you can eliminate the use of the heightmap editor for this.
There are a few good programs that can do good RAW Maps, I know about GeoControl but there are others like World Machine and the one mentioned by the MERP team leader.
Oscape (AFAIK ) can create good lods for Oblivion and Skyrim.
So there is a workaround.