That's true, for some strange reason NI has made clusters and arrays selectable using tab and had neglected the fact that normally that is not very interesting to do...you always want to jump directly to the content, highlighting the border just makes the interface behave non-standard...(comments from NI?)
A half solution is to add a two controls, one outside and one inside the cluster and hide them from view by putting them outside thw window / cluster border). Do not make the cluster selectable by tab-navigation, but read the highlight property of those two controls..if the control outside is highlighted highlight the first text control in the cluster...Now if the user tabs and highlights the hidden control inside the cluster, highlight an object outside the clu
ster.
The tab order inside the cluster (and the order of the elements...) can be set by right-clicking on the border of the cluster and selecting "Reorder controls in cluster..."