I think there’s no good reason why ships below r15 should have 4 or less seed chip slots. They are already at a disadvantage as lower rank seed chips are weaker than their high rank counterparts, in addition to the ships themselves generally being weaker, so I don’t think we have to expect r14 and lower ships to suddenly take over all content that allows seed chips. However, players would have more options, and that’s always a nice thing.
There’s no solid reason as to why lower rank ships have less slots to begin with. The PvE meta is dominated by R15+ Recons and Engineers and Open Space is almost only Engineers if you want to get any work done at all.
Giving 5 slots to all ships would help, but removing the dismantling cost would help even more since it’d allow for more player freedom and would probably help diversify mid to high level PvE at least to some degree.