It is possible to change the default names in the BLX HMI Matrix which pr. default is a tagname. (see image 1)
1) Open HMI editor from System --> Configuration --> HMI editor
2) Open the BLX editor and add a name in the upper right corner (see image 2)
3) Save and open the matrix in BLX. It may be nessary to do a refresh to see the name changes.