Arranging thumbnails freely with gaps

In a development environment, I need to have quick access to several pages on several instances (dev, test, PROD). I organise this by a matrix where each column is one environment.

my problem is, with SpeeDial for chrome, I cannot arrange it because all icons line up left to right without being able to insert a free space thumbnail (it even could be the + thumb). Not all environment have all the pages like others (a cluster may not have a config page, but DEV and test would, etc.)

Please arrange that I can freely position any Thumbnail wherever I want INCLUDING a spacer thumb like the + ones:

[PROD Home][TEST Home    ][DEV Home]

[      +            ][TEST Console][DEV Console]

[      +            ][TEST Settings][DEV Settings]

Do you see my problem?

Thanks!

Carsten

[Update] Using an about:blank killed whole SD!! Even import was not working anymore I guess as of the "cannot get pagecontent http://about:blank" something went internally wrong in the database - check error console. Even import did notn work and got stuck in Step2. Had to re-install - here I am struggling with refreshing my dials all at once - others have reported issues as well