Hi,
normally multiple project with the same systems where possible, where during the approval the popup raised and get the confirmation from your end to get the confirmation of relevant active maintenance cycle.
but not sure of your case, because your case the change in Transport route too.
For 4 tier already two delivery routes follows from QA, so For 4 tier if the TR released from Dev it moves to all qa, pre prod, prod. later you import either manually for nc and automatic for UC.
now for 3 tier, here your transport route follows only PRD ( which pre PROD earlier). logically its possible. but never checked before.
make sure while defining the system role in project creation and run the charm consistency check, if it ends green, no violation.
please check.
Thanks
Jansi