@aashry Unfortunately we don't do too much ROS work around here so I'm not sure if someone else will respond with a better answer, but... I would highly recommend pointing a fan at your VOXL while doing development on your bench and see if that affects performance.
As you mentioned, VOXL2 is much more powerful and will likely perform much better in all ways (also much more developer friendly since it's runs Ubuntu 18 as opposed to VOXL's yocto build), but it makes sense that you want to get things working on your current hardware