consider, instead .. A different project..
a wider range 3, or 5, speed IG hub, + the dual chainrings ...
avoiding the frame spread. [a PIA], the rear hub will function in 2 ranges...
made wider by the 2 different chainrings..
RD becomes a chain-tensioner, staying centered over 1 cog on the hub
providing take up of chain slack to use both chainrings..
and simplifying the bike you have, making it more practical , a different use.

Then, go buy the latest stuff, as a whole bike purchase, for the racer style bike need.

From the Local Bike Shop ... The complex new stuff is a different sort of kit.
better to have it sorted out with nearby help if needed.
end of season there is motivation to sell bikes, rather than pay inventory taxes
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