All credit goes to the ISG group of D-ITET at ETH
Funny enough renku doesn鈥檛 seem to mind the project being on an LFS. Only the home directory.
I filed a bug report: Unable to acquire lock when home directory is mounted with NFS 路 Issue #3669 路 SwissDataScienceCenter/renku-python 路 GitHub
I also found a workaround:
$ HOME=/scratch/mrawlik renku