While model history is being retrieved for display to the requestor, then the model will be blocked for any other use. It should not be needed to block the full model since this display activity cannot compromise the integrity of the data.
We have recently consolidated into fewer hypermodels, which each contains more users. The users continue to perform history lookups with same frequency, whereby all users more often will experience to be blocked.
To make the blocking worse with a consolidated model, then the time for individual lookup (and blocking) takes longer due to the more total model changes in the consolidated model.
By avoiding the blocking will especially hypermodels and other large-scale models be better supported.