Could you share what those would be. This could be done by someone who've gcp editor access. This could be behind auth and can be called via API. We've written bots to give ssh access for anyone in org.
Infact gcloud have the feature its just cumbersome https://cloud.google.com/compute/docs/instances/adding-remov...
Apart from that the login to multiple machines at same time is something personally i needed to check status on multiple instance of apps, dbs, kafka, cluster etc.