My favorites are zip ties with the screwhole tab and the whtle plastic Romex staples with the 2 nails (replaced with long small diameter sheet metal or wood screws.
I like wood framing that can support me if absolutely necessary and drilled 1 X 4s woud be highly suspect for failure
I doubt it would be an issue. If your weight is distributed over one board it shouldn’t be a problem. If built properly your weight should be distributed over many boards.
You can drill all the holes you want in the side of a support material, wood or steel, alum,etc. it’s when you notch or cut on the top or bottom of the material when used as a horizontal support is when you weaken it.
We have built the benchwork for our new club layout entirely out of 1 x 4s and we can climb on it as we wish. We have even drilled six or so 3/8" and 5/8" holes through most of the supporting structure. It is very solid.
The only difference in our case might be that we have screwed and glued 3/4" plywood to the top of the benchwork so the load is distributed over more than one or two boards.
The ‘U’ shaped metal staples are meant to be snug against the wires to keep them from moving. I have installed tons of these mostly to hold romex in place. But romex is double insulated. I don’t think you would ever have any problems with using these staples on your layout, but there are better solutions.
I drilled holes through 1x4 joists as I built the bench work, and ran bus lines through them. For subsequent work, I bundle wires and wrap them with cable ties and then hang the bundles from cup hooks screwed into the joists.
The nails won’t hold in the foam. Cut out a small square a plywood about 3"x3" and hot glue it to the foam. Use that as your plastic staple surface.
BTW: Those plastic staple clips with nails on each side are what I use. They work great. It’s easy to loosen then if you need too. And they never once cut through my insulation. I also use zip ties
Going along with Space Mouse and Mr B with the cuphooks, however, I would add to get the ones with the tab that keeps the wires from falling off the hook. If removal is needed, just slip the wire out under the tab.
I would never use big staples for wiring. They can damage the wire, they can damage the wood, they can damage you if you stick them in too far (or miss) and you run your fingers into the ends, etc. They also are a pain in the butt to remove, and hammering them in can cause problems (I’ve hit my own fingers too many times using them on Romex).
I also don’t like putting them through holes in the joists. Moving joists or wires becomes a chore, either pulling all the wire back through (and disconnecting all the feeders) or cutting out the hole(s) in the joists.
At my club (and on my old layout), we use plastic loops like this:
I think these plastic loops are the best solution for stringing wire. They won’t scuff the wire, they are easily installed/removed, they are available in a large number of sizes, and once screwed in they won’t fall off or allow the wire to fall out. They are also available in black or white, and at my club the 1/4" black loops are for the track bus while the white loops are for power feeds and other things.
Thanks for the picture of the helpful clamp. I purchased something similar that’s used for securing telephone wires. Avoiding pinching them or running a nail through wires is always a good thing!