Hi Dev,
[quote user="Dev Joshi"]Are there any other devices or driver configurations which would allow for this sort of variation in string length[/quote]
There are a lot TI solution to drive LED string with different length (LM3424, TPS92690 and so on). The main criteria is possibility to provide SEPIC or buck - boost topology.
Also be aware that universal solution will give you worst efficiency than solution which is tuned for specific LED string length.