Unfortunately, you are getting the run around from Apple Support, who according to your post, is taking the position that this is new problem that very few users have reported.
Not sure how far back that you have read in this thread, but here is a portion of my previous response:
The issue has attracted the attention of major Mac publications.....for example....
http://www.macworld.com/article/3170844/macs/when-backups-go-bad-the-problem-wit h-using-network-drives-with-time-machine…
Frankly, I have tried to be patient for years, but have grown tired of being told that "we are working on it" when I check with Apple on about a quarterly basis regarding this issue. Don't know how far back you have read in this thread, but here are the possibilities from which to choose:
1) Apple has been "working on it" since Snow Leopard, and they are still "working on it"
2) Apple was "working on it" at one time, but is not now
3) Apple never really was "working on it"
If the information in your post is correct......so he said the last option is to escalate up to the engineers......makes Apple look quite silly, since the "engineers" have known about this issue since the Snow Leopard operating system was introduced.
If you can, please report back after your call back from Apple to let us know what the current state of things might be.