...Rear brake caliper barely fits setup as 140 with the br002 model ...

Do you mean the frame has not enough clearance for the calliper?

I also ordered this Frame 10, May on Aliexpress. BXT did not ship out the frame yet.
I have asked about the status, their reply is always same. "This frame is currently missing some accessories. At present, the supplier of accessories has no inventory of accessories for the time being. The factory needs to wait for the frame parts from the supplier."

According to them they also don't know when they get parts to build the frame.

I am not sure how long I should wait further or better cancel this frame.

Is there anyone having same issue?

Some patience is required when you are your own importer.
Remember they were quite hit by harsh covid rules not so long ago.

Strange, I've advised Magene HRM bands, powermeters and home trainers to folks here and all are happy. And their support from Aliexpress messaging, has always been great.

When I swap wheels with different hubs (dt-swiss, carbon-ti, hope, novatec), I generally need to realign callipers.
Are you having them off to the point where you can't even properly align the callipers?

Almost done with a new VB-186, but while working on the rear derailleur, I realized that instead of shifter cable housing I used brake cable housing. Anyone done this before? Is it no big deal or should I redo all my cabling?

If you used compressionless housing, you 'll be fine.

bit of a noob question but how do you build/service a wheel without access to the nipples? Thank you

First, cut the thread of an old spoke.

Screw it to a nipple.
Put them in the rim by the valve hole.
Use a magnet to drive them through the spoke hole, and get the spoke bit out.
Squeeze the nipple with your thumb.
Unscrew the spoke bit.
Screw the spoke.

Repeat this between 19 and 31 times per wheel
It is easier than it looks, after a couple of wheels it is very fast.

... I usually puncture the rim tape with a needle first, then push the valve through, so the hole is round, and as small as possible.

This ! I do exactly the same.
Using a torch light from inside through the valve hole, to pierce it right in the center.
Then with the valve core srewed 

Trying to figure out if they'll send them to me left rear right front before buying a set, do these use mineral or dot?

Just ask them, Aliexpress sellers are generally quite responsive

I planned to build for riding more than 100km (70-80% pave road)
What I mean is for relaxed bike, not sporty bike.
with 700 with light tyre and wheels.
Now I am looking for tantan GR044
https://www.aliexpress.com/item/1005004310989115.html?spm=a2g0o.store_pc_groupList.8148356.72.179431ffyVym4Z&pdp_npi=2%40dis%21USD%21US%20%24569.00%21US%20%24426.75%21%21%21%21%21%400b0a050b16540920677201880e8436%2112000028709493658%21sh

that frame can ship to my country.
But I don't know about geometry.

Look at how the stack/reach from the aliexpress geometry picture compares to your current bike(s).
You can check with https://geometrygeeks.bike/ too.
Usually gravel frames are more relaxed, but not always.

From memory, Tantan doesn't have a really good after sales service in case something happen.