[Road Bike] After much deliberation, I'm finally upgrading my groupset (105 -> Ultegra)

I bought a road bike one year ago.
[Original Specs]
Frame, Fork, Seatpost: Carbon
Shimano 105 Di2 (12-speed) electronic groupset
Handlebar / Stem / Wheels: Aluminum
At the time, there was a 25% discount, so I purchased it for about 3 million KRW.
Since then, I've been having a lot of fun riding it.
I've ridden from Seoul to Chuncheon, Yeoju, Incheon Ara Waterway, and Chungju.
On weekends, I've been visiting Yangsuri and so on...
As I rode more, I became increasingly interested in the weight of the bike,
so I upgraded as follows:
- Cassette: 105 -> Dura-Ace
- Rotors: 105 -> Ultegra
- Crankset: 105 -> Ultegra
- Aluminum wheels -> Carbon wheels weighing around 1200g
- Handlebar: Aluminum -> High-end carbon handlebar from the same manufacturer
The bike weight, which was 8.6kg when it was stock, was reduced to 7.3kg.
After that, I rode well for almost a year without any additional upgrades.
However...
The levers, front derailleur, rear derailleur, and calipers (brakes) are labeled as 105,
but the crank is labeled as Ultegra...
After debating for a long time about whether to match the components,
I finally ordered: levers (2), front derailleur, rear derailleur, and calipers—all Ultegra (12-speed Di2).
Once everything is replaced, the entire groupset will effectively be upgraded to Ultegra Di2 (12-speed), except for the cassette, which is Dura-Ace.
Now that I've done this,
I realize that if I had just bought the Ultegra grade from the start, it wouldn't have been this much hassle...
In fact, it's actually costing me more money.
But since selling my current bike and buying a new Ultegra bike would cost even more...
I'll just finish the upgrades on my current bike
and ride it for a long time.
To be honest, whether it's 105 or Ultegra, there's no difference in the actual riding experience,
and although no one else cares,
it does provide a slight boost to my mood.