Quoted from EalaDubhSidhe:Got a solution to the in-line and lock conundrum now that arranges the features in a different way, while allowing others to still chain together in the way that I want. Turns out the biggest consideration was available space - I was also hoping to create a captive ball chamber with five star rollovers and an end target in for variable points depending on the hit strength and number of lit stars, but there wasn't room for all that in one line. This different arrangement should work well though and be encouraging to shoot for, so I don't think players would be disappointed.
Either spring for Stern's new opto roll overs from TWD (if you actually build this) or use optos instead. Olds-chool rollovers are a PITA.