I didn't use Flexio but I was using Wagner 518080 Control Spray Max HVLP with acceptable success (if you aware about overspray issues). And you need to tint latex paint otherwise it sprays unevenly (orange peels). I used with latex paint and watebased poly. I wouldn't try to use it with oil based things. Likely you will not be able to clean the gun. Also you need to learn how to use it

It's not so obvious how to choose air-flow and how it affects paint volume.
Bottom line I will leave it for outside work and buy something better for woodworking.