Hi, unfortunately for you I really believe that the spacers of the Kocevlo handlebar you purchased are not compatible with the frame.....they have an elongated shape for the SL8 frame and do not go well with the R088 frame (a few pages back you should find some photos of my first Elita One handlebar and related spacers kit which are identical to those of the handlebar you purchased).
I have been stuck with the assembly of the frame for some time, waiting for a new ULLICYC handlebar to arrive....the spacers kit that arrives with the handlebar is identical to the one in the photo you posted and that you would like to build yourself (see attached photo), theoretically it should be fine, but I noticed that the piece through which the hydraulic cables pass has a different finish compared to the other pieces/spacers.....I therefore believe that it is not part of the original kit supplied with the handlebar, but that it was produced and added later.
As soon as I find the time I will try to finish the assembly and then I will let you know....if this kit doesn't work well, I think I will opt for a new handlebar with completely internal passage of the hydraulic cables and a front hole for fixing the cycle computer (always to use the MagCAD support for Bolt V2 that I purchased).
https://it.aliexpress.com/item/1005006286213042.html?spm=a2g0o.order_list.order_list_main.23.673c3696J5NiSK&tblci=GiCC4m7NjPqiKcqZte9zc6nQwymmLm1_jCpQPCF6yretFSCnqXUogey87_rbk6idATC062M&gatewayAdapt=glo2ita
Hey Bonus, I wanted to follow up on this. Your posts were very helpful for me figuring this out. I got the spacer kit attached, and it fits perfectly with the Kocevelo Roval Rapide clone. Couldn't be happier honestly. See attached photos.
Nearly done with the build now, just need to wrap the bars after I take it for a spin.
Bought everything on Aliexpress:
Full Ultegra Di2 groupset
EliteWheels Edge
Kocevelo integrated handlebar
Ryet 3D saddle
Frame is color #1 glossy.
The only issue I had during the build was the battery in the seat tube fitment that everyone has talked about. I also made the mistake of pulling all the slack in the di2 wires up the seat tube and then trying to jam it all back in like I was loading a musket. That didn't work so I had to pull some of the wire slack and stuff it into the downtube.
I also did have to sand down the brake caliper mounting points a bit.
All in all, it was pretty easy considering it's my first time building a bike. It comes in right at 7kg without pedals and bottle cages.