Not rigid enough? working with 6061 Aluminum

If aluminum is your main work material, you’re going to be putting some serious time in. The machine is capable if it’s your option.
As @Zach_Kaplan said, it’s all about the toolpaths.
Here are some pics and video of a recent Aluminum/Carvey job.
I ran this with a .125" spiral, single flute bit.
Feed 250mm/min.
Depth per pass was an experimental 3.5mm with an optimal load of 0.127mm. Generated in Fusion 360.
I ended up stopping every once in a while to remove chips and, eventually, add some WD-40.