Sorry if I’m beeing inexplicit.
Regarding v3. This is my result:
Working: https://xx.yy.zz:5000/v3
Not Working: https://xx.yy.zz:5000/v3.0
I belive this is a good info to submit to the docs and I will look into contribute that.
Regarding Swift. Yes I got restic to connect to Swift on the Linux machine, but at the time, not with Windows.
Regarding using cmd instead of powershell, look at this… It works! 
C:\Users<hidden>\Downloads\restic_0.14.0_windows_amd64>set OS_
OS_AUTH_URL=https://hidden:5000/v3
OS_AUTH_VERSION=3
OS_IDENTITY_API_VERSION=3
OS_PASSWORD=hidden
OS_PROJECT_DOMAIN_NAME=hidden
OS_PROJECT_NAME=Management
OS_REGION_NAME=hidden
OS_TENANT_NAME=Management
OS_USERNAME=hidden
OS_USER_DOMAIN_NAME=hiddenC:\Users<hidden>\Downloads\restic_0.14.0_windows_amd64>restic_0.14.0_windows_amd64.exe --verbose=3 -r swift:limecon:/ init
enter password for new repository:
enter password again:
Fatal: create key in repository at swift:limecon:/ failed: repository master key and config already initializedC:\Users<hidden>\Downloads\restic_0.14.0_windows_amd64>restic_0.14.0_windows_amd64.exe --verbose=3 -r swift:limecon:/ backup .\brandbil
open repository
enter password for repository:
repository ebdc701c opened (repository version 1) successfully, password is correct
created new cache in C:\Users<hidden>\AppData\Local\restic
lock repository
no parent snapshot found, will read all files
load index files
start scan on [.\brandbil]
start backup on [.\brandbil]
scan finished in 0.705s: 1 files, 73 B
new /brandbil/brandbil200.txt, saved in 0.008s (73 B added)
new /brandbil/, saved in 0.025s (0 B added, 0 B stored, 370 B metadata)Files: 1 new, 0 changed, 0 unmodified
Dirs: 1 new, 0 changed, 0 unmodified
Data Blobs: 1 new
Tree Blobs: 2 new
Added to the repository: 677 B (884 B stored)processed 1 files, 73 B in 0:00
snapshot bafc0d10 saved
So the solution for me is to use cmd onwards. How ever, as powershell is gaining more and more traction within Windows Server, I would gladly like to try to help out getting it to work.