Sorry, but I just gotta do a little bragging. I finally got started on the new N scale layout in our new (old) house. This is my 4th layout and each has had succcessively better benchwork, but I even surprised myself with the latest.
The pic in the link below shows me kneeling on top of the benchwork doing some work on the track lighting system. I had no qualms about doing it. The whole thing doesn’t wriggle, not even a bit. It is absolutely rock solid. I can even walk around on it!
It’s anchored into the wall, but the real secret is a layer of cheap paneling under the foam that is screwed into the benchwork, spanning joints that might otherwise be less stable. It apparently lends an incredible stiffness to everything. This link shows the paneling before the foam was added.
You’ve just discovered one of the dirty little secrets of benchwork construction: you don’t NEED to use 2x4s to have solid benchwork!
My last layout was 1/4" plywood and 2" foam. While the upper decks were attached to the walls with shelf brackets, my lowest level was built on top of a VERY simple box frame, made of 2x2s. I’m about your size and regularly walked/kneeled/crawled all over that level (how eles could I work on the upper levels?). Local modelers who were wedded to 3/4 ply and 1x4 L-girders would regularly be shocked to see me hop onto “that wimpy foam benchwork” to point out something.
And foam WILL dent, but not badly. Certainly nowhere NEAR as badly as hardshell if you tried to walk on it!
I was concerned about denting the foam also, but a few hours after the work was done, I couldn’t find the small impressions my kness had made. The foam had returned to its original shape.
You did a fine job with your benchwork. As for the comment about not needing 2x4’s…well, if you look at weight of the thread author, I would say he is about 165 pounds. Some of the MRR’s that I have seen go well over 250 pounds. So if they were able to climb up onto the table top, I dare say there would be some anxious moments shall we say!!! LOL
I agree with greyfox. If that was me, along with the anxious moments there would be perhaps reconstruction work and a visit to the hospital. If it works for you - great. As for me I think i will go with something a slightly more substantial.