When members are merged any design parameters they have are lost. If members that have the same design parameters are merged, the newly created member should retain those parameters. Also, if the members had code checks done on them before the merge, the new member should remain in the CHECK CODE command.
The current way of merging is so inconvenient that I seldom use it once I have assigned design parameters. I delete member(s) then change the connectivity of the remaining member, then get rid of any nodes left over. This is horribly inefficient but it's easier than going back and assigning design parameters after they are lost due to merging.
Thank you for posting this idea. Finding a good way to determine the attributes that should be retained when members are merged is certainly a good idea. The challenge though is to determine what is the right action to take.
1) If an attribute is assigned to one but not the other(s)
2) If an attribute is assigned with different values on the various members
Rather than remove parameters, would a suitable compromise be that a choice is offered to say which member the parameters are taken from?