I do this on my ugly bike. Fortunately it has external cables (except rear brake is internal), but I have the process (bar swap, saddle swap, reattach cables and tune the shifters) down to about 30 minutes now (a little more for the wheel cover)



Full cockpit swap, so a) I can use a really slammed stem to get the pads low enough for a good fit, b) bar end shifters are so much nicer than using the STIs, and c) I don't have to worry about attaching and removing the clip ons every time and adjusting their fit. Everything is totally repeatable on the fit.

The second seatpost and saddle is also a 1 minute swap and the forward post and proper saddle is a necessity for a good position.
Removable/replaceable cable end caps are a massive bonus, keeps the cable ends in good condition so they rethread smoothly. https://www.cyclingdeal.com.au/...shifter-cable/CED-BD