Scratchpad board layout progress

I've just about completed the layout of the Scratchpad board for my Intel 4004 CPU recreation. The only big changes in the layout since 2016, other than the signal routing, has been to reorient some of the decoding sub-circuits on the right side of the board.

The ratsnest command now reports no remaining airwires (unrouted nets), and the DRC reports no errors. Hypothetically, I could generate Gerber files from this and have the board fabricated.

So what's left?

• The DRC parameters I'm using are left over from using PCB-Pool. I don't have good Eagle DRC files for JLCPCB, so I need to create some. My spacing is wide enough that I don't expect to need to move anything.
  
• There is no decoupling between the VDD and GND planes yet. I added four tantalum capacitors on the corners of the Instruction Pointer board, and I'm going to add the same plus some ceramics to this one.
• I'm going to add outlines and labels to the silkscreen for the remaining sub-circuits, as I did on the Instruction Pointer board. I've found these very helpful when probing the board (and they look nifty).
  
• While I'm pretty sure the clock issues I worried about are a non-issue for this application (nothing is edge-triggered here), I'm still thinking about adding footprints for a couple of resistors between the two clock lines and a pair of unused pins on J1.
  

Both PCB-Pool and JLCPCB have produced excellent boards for me. My experience with PCB-Pool's customer service was stellar, with fewer language and time difference issues, but I really have no complaints with JLCPCB. The biggest difference is price: PCB-Pool would charge me $175 for one board ($248 if I want a second as a spare), while JLCPCB will charge me $39 for five boards. While shipping charges are a bit higher from China than from Europe, I'll pay a few dollars more in shipping to save hundreds in product costs.

Speaking of shipping charges, it pains me to pay $24 in shipping for $39 of product. I could save $10 by using the cheapest shipping method, but that would take 3-4 times longer and probably isn't trackable. My next order will probably include both the Instruction Decoder and Arithmetic Logic Unit boards, as my current test jig doesn't have enough I/O pins available to test them separately. I'm expecting this will reduce the shipping cost per board. They're also laid out as 6-layer boards (this one is 4 layers), so the product costs are higher ($79 per design) for the same shipping cost.

I'm also considering having the solder stencils fabricated by OSH Stencils rather than JLCPCB. For some reason, adding a single minimally-sized stencil to the JLCPCB order adds $7 for the stencil and $8 to the shipping estimate, though I think that shipping estimate is higher than what I was actually charged for my last order. A Polyimide Film stencil from OSH Stencils would cost about $25 including shipping, which is about $10 more than a steel stencil from JLCPCB. However, it's easier to position a film stencil, as it is more-or-less transparent, and its flexibility would make it easier to populate the board in portions rather than all at once.