that works on one of my frames but on the other not – I have outer from brifters to a cable stop on the downtube, then it runs naked inside the frame under the BB and along a chainstay to pop out for another length of outer to the derailleur.
It’s not so bad if you do F&R and rear brake at the same time as you can then take the BB cable guide off which opens a bigger hole in the BB but if you don’t want or need to do all three, getting the cable out through the cable sized channel in the BB guide is a mare. But feeding a length of thin tube up the downtube from BB to cable stop, and another from BB along the chainstay using the old cable as a guide first makes if far easier.
Just wondering how much easier still the real deal is, and if it’s worth the cost.