Widening the weight range.

Not sure most have the tools and skills even for building a Mirror these days. Probably some 'elf-n' safety nonsense about using resin too.

And of course the proven performance variances within a class enabled by the relatively large building tolerances necessitated by all this home building are proof as to why a polars-based dinghy rating system will not work

This needs a 60s style Giles cartoon, pie-eyed blokes in a shed being accosted by angry wife in curlers brandishing a rolling-pin, "but we're only half way thru stage-one, dearest"

time poor, cash (or credit ) rich - you go out and buy one ready-to-sail

time rich , cash poor- depends if you have the skills,  if you have the skills to make a boat measure to modern rules you are likely  to want to  have control over  materials  specification and fitting choice within the rules  ( which  would further pump up the ppirce of the thiese mythicla 'boat in a box packs)

if you don't have the skills even with pre cut panels and simplified  construction methods you'd still have issues making it measure  and if the boat doesn't measure it's money flushed down the drain

Bell went to the wall as they could not make money from the model being proposed , I dread to think what  the courier/ delivery firms would charge ot deliver a 'boat in a box ' kit  even with a multi piece mast ... it would be too heavy / large for the  parcle boys  which puts it into the realms of the  commercial carriers who aren't set up for  residential multi dropping ...  where a set of plans  can be  sent by  royal mail parcels / your choice of document courier / as computer files to  the local large format printer / work CAD monkey ...