zoom - unfortunately it was 'pulled' from this release, as it causes performance issues.
as you correctly point out, its not just something you can easily add, without causing other issues.
however, its something that is slated for the next release and the work is already 'in progress' , but the release has quite a few things going into it, so its probably a while away yet.
(as stated before 1.0.12 is stable, so the next release was a bit more ambitious, tackling some issues under the covers)
so yes, its a priority, but Axoloti is not made by a software house, that can just bring in extra resources, so its not really a question of if its 'urgent' or not
if you want to help, then you can contact @johannes, you will need to be an experience Java programmer with Swing/UI frameworks and experience with the model view controller paradigm.
if you cant do that, but have development experience, another option would be to either look at the 1.0.11 version which contained zoom (note: its not the latest release of 1.0.11, you'll have to dig to work out which it is) , or one of the development branches (probably experimental is best... master if you want to help development) BUT this is not supported i.e. be able to figure this out yourself ... also you will not be able to contribute to the community library, and of course development versions contains bugs, and potentially features missing/partially complete.
... this is not too 'hard' if your experienced with Git, a bit of java, and general build tools, but its not some I can really walk you through, as too many pitfalls if your not sure what your doing.