Hackers Help: Big over sofa table – need suggestion on reinforcements.

I’m using a Nornas side table, the larger Knagglig box and Slugger castors to make a C-style table for plenty of desk space.

IKEA NORNAS side table
Photo: IKEA.com

The idea is to turn the table onto its end, so the table top is facing sideways portrait-ly, break apart the Knagglig box and nail the slats (in yellow) across the top table legs, and attach the castors to the bottom of the table legs (in blue).

I’m doing this instead of just getting a Vittsjo Laptop stand because
a) I prefer the look and feel of wood
b) I know I can fit castors to this (I’m unsure with the Vittsjo, and it’s not as easy to work with metal)
c) I can still use this as a side table if required, just by tilting it back to the original feet (The glass in the Vittsjo would fall out, and securing a new top to the “long side” of it would be beyond my skill/confidence)
d) I can further modify/add things to it if I wish later (such as a keyboard drawer or something)

In the “as intended” design the table would have been able to take a lot of weight, but this would change for my alternative angle.

What would you guys suggest to help strengthen it? I was thinking of using left over parts from the box as reinforcing struts, and screwing them or use dowls and woodglue to strengthen the joint.

Please see picture for clarification.

IKEA NORNAS as a big over sofa table

~ Cathy