[ijkkquik] Ultimately metallic stars

The universe has progressed from Population III stars to population II to population I.  What happens next?  (Historically the populations were named in the order of discovery, so the next one should be confusingly named population IV.)

A star goes supernova providing matter for the next generation of stars.  Each next generation cares primarily about hydrogen.  How much hydrogen survives being consumed by a supernova bound star during its lifetime?

It would seem not much, so each generation of new stars becomes significantly more metallic.  Hydrogen seems never replenished, except maybe through neutrons emitted in spontaneous fission of heavy elements created in a supernova.  (Helium similarly through alpha decay.)  So the amount of hydrogen available decays exponentially with generation (and the generations of supernova bound stars are short).

It might be that the more metallic a star, the more violent the Wolf-Rayet process, expelling much of the hydrogen atmosphere before it can be consumed.

What will stars look like when the supernova remnant gas and dust clouds from which they form are (say) 90% iron?  Perhaps large brown dwarfs.  Or forming directly into white dwarfs or neutron stars.  When will we get to that point?