I don’t agree. A series is not a work and modifying the function of the Work in that manner is a band-aid solution.
In a past life, I discussed ways of dealing with author series: Series by authors - how to manage
It is critical that BB implements a system in the near future as the database is expanding and there are already numerous series. The longer a decision is delayed, the more difficult it will be to implement any type of system.
If adapting the Work to collect a series is the only solution, then I totally agree that keeping track of them is essential.