The last time I checked out the Asus Tinker it was still suffering from horrendous software support and cost nearly twice as much in the UK (which it still does, £32 vs £55). So unless you NEED those extra features, I strongly disagree.
(That way you can prepare image that boots both on RPi and Tinkerboard)
Example hybrid image for Tinkerboard and RPi is here (based on Ubuntu): https://files.husarion.com/husarion-core2-ros.img.xz (unfortunately the build scripts are not public yet)