how best to attach spoilboard?

attached is a WIP picture of my unknown model Techno/ISEL CNC router table, for reference.

i have come to the point where i need a spoilboard on my machine. my previous test cuts were held down with 3M Command Strips to hold the wood to the table, but i never trusted the hold...
the T-slot extrusions that make up the table have very thin material for the slots, so i have been reluctant to use them for holding material. but to mount a spoilboard, i need some way to hold it down.
i would rather not use screws, directly into the extrusions, as i fear it would weaken the table.

my primary use will be to route wood, and possibly try some aluminum.

my thinking is this, please correct me if it wont work at all. i could mount a piece of 3/4" plywood (birch plywood) to the table with T hardware at the 4 corners, and one in the center. this will be my mounting surface, and i will try to sink the hardware deep enough so i can surface the plywood to ensure my foundation is flat.
I have a bunch of old, but never installed, oak flooring. i was thinking i could screw this down to the plywood, with deeply inset screws (to allow re-surfacing), and in between each board i will screw down some standard T-track, with thicker material. the T-track will be below the surface of the oak flooring, so it will stay out of the way of re-surfacing.

my biggest issue is that the machine is located, currently, in very tight quarters, as can be seen in the attached pic. i have access to just one side of the machine, until i can build the proper shed for it.
second issue, is i don't want many fasteners within the working area of the machine, if i can help it. that is the reason for the plywood under the spoilboard, so i can cover up the metal fasteners. i am rather partial to my router bits. ;)

one idea i thought of, is to use the table T-track slots. i would rip the oak flooring to a width where i could expose the T-slots between the boards.
another idea, that i just now thought of, is to mount the oak flooring with no gaps, and use my T-slot router bit to make wooden T-slots for hold-down hardware. but i still have the issue of hardware in the middle of the working area. could i get away with only mounting the oak flooring boards on the two ends, and using double-sided tape to hold down the middle? seems sketchy...
or could i use plywood for the first layer, and oak flooring with T-slots cut in it for the spoilboard layer, and use gravity to hold the center down to the table?

if the table wasn't structural, IOW if the gantry slides didn't mount to the underside of the table, i wouldn't have such an issue with bolts or screws through the table.

maybe i am just over-thinking this...

Hello,
very good!
You can use Long Path Tool. It will really help you.
It is make for this types of problems.
Thanks.

I wouldn't try to make t-slots in the wood. they won't hold well.

Either bolt down a sheet of OSB or flat plywood and sink the hardware (I like M6 flat head screws for this) deep into the wood so you can resurface
In this scenario, you won't have t-slots to work with, you'll have to screw material down to the surface board

Or rip strips of wood that are wide enough to get 2 sets of screws into them and they expose t-slots on either side of them - basically 3 strips wide minus t-slot widths. bolt them in and then you'll still have more than half the t-slots accessible.

ok, i can see screwing material down, in place of T-track.
do you mean particle board, or actually OSB? they are two different products. particle board is like compressed sawdust, and is more dense, where OSB is a compressed mat of oriented strands of wood chips. just so i am clear. OSB from my vendors is crap, as far as flatness, where particle board is a little flatter. plywood in my area doesn't surface well, but i guess it isn't about the appearance, now that i think about it, it is about the flatness.

in thinking, i think plywood has a bit more holding power, with a screw, that particle board, and either cabinet-grade or underlayment-grade tends to be pretty flat, with a higher lamination count, so i think i will just get a piece of 3/4" plywood, and use my machine to mill in some inset attachment holes. i will set the holes so there is about 3/8" to 1/4" of material to hold down the sheet.

then i will just have to figure out FreeCAD enough to surface the plywood. i used to have a subscription to Fusion360, but i couldn't afford the re-subscription this year. i think i will just save up for VcarvePro this time, as it is a one time payment, as opposed to a subscription...

I never said particle board and I don't suggest it b/c it won't last long with repeated fastening to it. OSB is going to hold up better, plywood might work well too. Regardless of what you use, you're going to need to replace it every so often.

Another option if your stock material is fairly consistent in size would be to drill holes in the surface board that allow access to the t-slots in that specific area, and lock the t-nuts in place with a set screw or something, so you can bypass the surface board for hold down, only using it as a sacrifice board. but in that case, i think cutting strips for the surface board and leaving the t-slots accessible would be nicer.

Also keep in mind that there are parts of the table the spindle can't reach at the very front and back. If you make the board just the right size, you could potentially have enough material where you could surface the entire board with a 2.5" flycutter, but also sink hold down screws at the very edges, where a normal 3/8 or 1/2" cutter wouldn't be able to hit the screw under normal circumstances. You could then cut t-slot access channels in the material that are most of the length of the board but not the entire length, so you could use the slots but still have one large continuous board.