I've used https://bikeinsights.com/ for frame comparisons.  Just pick your current bike frame, then overlay with the 066 frame.  This will give you an idea which frame size will be closest to your current bike.

For example, I built a medium 066 frame, which is a bit too big for me.  I have a medium Giant Defy Advanced and I'm very happy with it.  A small 066 would have fit me much better than the medium.

If you think about it, the distance between saddle to the BB is governed by your inseam.  No matter which frame size you get, this distance will be the same.  Also same with the reach, your upper body and arm length will govern that.  If you look at the geometry between sizes, they differ very little, so in most cases, you pick the right stem length and right steer tube length to suit you.  The only thing you want to look out for is the standover height.  Bigger the frame, less the clearance between the top tube to your crotch.  And of course, bigger the frame, less exposed seat post, which is less aesthetic pleasing.   

Good luck with your build!

I'm looking at potentially buying this frame but I'm not sure if the large would fit. For reference I'm about 6'4" (193cm) tall with a 35.75" (908mm) inseam and currently ride a Cannondale Synapse size 58cm which fits alright. Comparing the geometry they look similar enough, curious to hear if any other taller riders have experience with this frame or if anyone has some advice on fitment/sizing.

I purchased this same crankset, except it has 2 chain rings.  I can't recall having any issues putting the crank together. 

My frame has BSA BB.  The crankset came with BSA30 bearing cups.  The spindle is already connected to non drive side.  the drive side is secured onto the spindle with a hex bolt.  The dust cap you're referring to is actually just a cap that keeps the hex bolt in place.  When you unscrew the hex bolt from spindle, this cap will hold the hex bolt in place, acting as a crank puller.  if you remove the cap then the hex bolt, the crank will stay on the spindle and you'll have a hard time to remove it.

I have always wanted to build a carbon frame bike with parts from Aliexpress.  I started gathering info and purchases in March 2020.  I finally got my bike together late summer.  Some of the parts took a very long time to arrive.

Here is a youtube link to the video I shot on the bike.  Parts break down is within the video description.

The frame is a BXT T800 road frame and drive train is Sensah Empire 11x2