Is secureblue really more secure if browsers have to be installed in flatpaks?

I also tried installing brave browser on the host system. That worked but when I attempted to run it, it didn’t launch. I tried using the with-standard-malloc command you recommended but I first got a “permission denied (13)” error and then when I tried running the command with run0 a “fatal allocated error: invalid uninitialized allocatator usage” error