Sturmey do a 3 speed with 135mm spacing, 6 bolt disc mount and thumbshifter – less than £100 for everything.
Lighter than an Alfine and felt much more direct and less mushy (pawls rather than roller clutches). Proper direct drive in middle 1:1 ratio (Alfine isn’t direct drive). Ratio mix was good for Lakes etc in UK, but broke me trying it in Austria (reverted to backup 7 speed derail. on a Hope ss cassette hub).
Downside is no sealing whatsoever, weak axle and chainline not very good with regular mtb cranks.
Nearly there, but not quite…..