Symmetry restraints

Hello,

I wonder is there a convenient way to implement symmetry restraints (e.g. for multi-chain proteins) in GROMACS?
I understand that the actual symmetry groups are probably not supported, but I guess it should be possible at least to restrain the in-molecule interatomic distances and/or dihedral angles to their values in an equivalent molecule (like MODELLER does https://salilab.org/modeller/9.24/manual/node113.html) or to their averaged values (similar to what was done here with NAMD https://onlinelibrary.wiley.com/doi/abs/10.1002/prot.22618).
The latter option seems to be possible using ensemble averaging, but some examples would be very useful!

Thank you