Right now, I'm building up a Pinarello Dogma F8 (not the DISK version), and
↑This is a photo after wiring is complete.
When there's wiring inside the bottom bracket, it can cause unnecessary trouble,
so it's something you want to avoid if possible.
This is a threaded bottom bracket, but with press-fit versions, I've heard of cases where
wiring gets crushed and severed when inserting bottom bracket components.
The F8's front derailleur hole uses the same location as the mechanical version.
I prefer running it near the front derailleur braze-on on the seat tube,
and with the 9150 electronic Dura-Ace, this position works out fine too.
All the wiring is complete.
All four cables exit from the down tube,
so if you tuck the lower junction box into the frame, there's nothing left in the bottom bracket.
↑Not like this
↑Like this.
That said, many frames don't allow this routing,
so it's just something worth doing if your frame permits it.
Internal battery
Front derailleur
Rear derailleur
Upper junction box
By the way, I happen to know quite a bit about the small components that come with the F8 frame
(→here).
Regarding the wiring, I've written similar things in the linked post as well.
↑This is a photo after wiring is complete.
When there's wiring inside the bottom bracket, it can cause unnecessary trouble,
so it's something you want to avoid if possible.
This is a threaded bottom bracket, but with press-fit versions, I've heard of cases where
wiring gets crushed and severed when inserting bottom bracket components.
The F8's front derailleur hole uses the same location as the mechanical version.
I prefer running it near the front derailleur braze-on on the seat tube,
and with the 9150 electronic Dura-Ace, this position works out fine too.
All the wiring is complete.
All four cables exit from the down tube,
so if you tuck the lower junction box into the frame, there's nothing left in the bottom bracket.
↑Not like this
↑Like this.
That said, many frames don't allow this routing,
so it's just something worth doing if your frame permits it.
Internal battery
Front derailleur
Rear derailleur
Upper junction box
By the way, I happen to know quite a bit about the small components that come with the F8 frame
(→here).
Regarding the wiring, I've written similar things in the linked post as well.