I realise this has been a popular topic since 2018, but i feel a new thread to re-raise the popular requirement might be worthwhile.
It would be extremely useful if when raising issues multiple users could be assigned and also the co-reviewer option added, as per within the RFI tools.
Whilst on topic of issues, it would also be useful to link markups directly to raised issues also. We use the issue functions for multiple reasons, such as IDC/IDR and also internal/disciplinary level checking for work in progress communication, prior to team coordination etc