The SCRS Crossbar is just a little extreme as it did come from a car that was used aggressively on the European Rally Championship.
The more common RSR Crossbar just uses a second flange to increase the stiffness and these work quite well but can still yield.
Adding a couple of gussets on the corners works quite well.
If you also make the Crossbar from a stronger material it will improve its reliability.
We made a small batch of RSR Style Crossbars using a material with the trade name of DOMEX 700MC. (They sold out quite quickly)
This material has been developed by SSAB for military vehicle applications.
It has a yield strength that is around 4 Times greater than a typical CR4 Deep Drawing Quality steel.
The yield strength is about 120000 psi but it retains the same level of ductility and weldability as more conventional mild steels.
It also retains its impact properties to very low temperatures.
For the relatively small quantities used in the engine crossbar the price premium is insignificant but the performance enhancement should be very good and prevent both deformation and subsequent failure.