The "lll*" was essentially a "budget" relaxation for WW1.
Once the slaughter had stopped, the "lll" remained the standard, hence the retro-fiting of some rifles. I understand that
Lithgow
in particular, went straight back to the standard "lll" in the early 1920's.
Long-range "dial-sights" remained in vogue on the SMLE and P-14 until the 1930s. Eventually someone twigged that they were a bit redundant, even given the less than generous allocations of machine-guns in the inter-war period. The deletion of the windage adjustment on the rear sight may seem a bit of a step backwards. I suspect that the elimination of something that could contribute to wayward shooting under duress ("Sorry, Sergeant, I forgot to re-centre my sights."), was not a huge loss; see sights on the No.4.
If you are banging away at obliging targets at known distances and with the aid of range flags, precise windage adjustments as per the wondrous thing fitted to the M-1
Garand
are a joy. However, once the rifle range has two-way traffic, the simpler, the better.