I just had an idea, when commenting in another thread, that the connector bars could be easily improved.
Currently, to connect all four lugs one has to start at the very top of the connector bar and slide along its full length, remembering to check 3/4 of the way down that the second pair of lugs is still aligned. But this is unnecessary and fiddly, particularly with the tented bar.
If you had a gap in the connector bar 3/4 of the way down, then the first set of lugs could be inserted or removed while the connector bar was only 1/4 of the way displaced. Alternatively, one could think of it as two short connector bars, one for each pair of lugs, connected together by a plain bar with no track.