I installed my set of Creo remote buttons today. I am not trying to be a downer but I think they are nearly as small and fiddly as the ones on the top tube TCU. And the install was some kind of hassle too. On my Creo Expert Evo I have removed the dropper post so the drive side port was vacant. I thought a no-brainer to run the two remote cables through it. But that port has one small and one larger hole. You can get squeeze one plugged cable end through the bigger hole but then there is not enough space to get the other wire with plug end through the port. I drilled it out just enough to get both wires through the port and up to the TCU. Getting your hands on a port cover with a big hole would be very helpful.
The sticky stuff on the back of the buttons just barely holds them in place on the bar so does require electrical tape to keep them in place prior to rewrapping with bar tape. Make sure you are comfortable with your placement before retaping things up as the remote buttons are still kinda small and you should ensure your fingies will be able to easily find them.
I almost for sure would prefer the bar mounted big button mountain bike unit with the single wire to the TCU. Unfortunately that unit has an even bigger connector to the TCU and would require a port with an even larger hole.
I think something like this might make things easier:
This is the Cbg My18 Diverge Left Side Icr Port For Shift And BrakeThis is compatible with the following bikes: Specialized Diverge Men Specialized... S176500009
www.amaincycling.com