You are likely thinks about a 3D printer type application. TinyG will do whatever the G code tells it to do, but all motion will be subject to the jerk motion enhancement that seeks to maximize machine efficiency (time spent on the job). Some folks have used the A axis to coordinate some variation in extrusion rate.
You may want to research the G2 project somewhat, it is aimed at providing the motion foundation for 3D as well as 2D motion.
https://github.com/synthetos/g2/wiki
tinyG is rather resource limited (memory, CPU).