Hello adesic, so you are using the i.mx6solo as a server in which end users would connect through an ip/domain right?.
I havent personally used the i.mx6 for this purposes but I have experience with the i.MX53, using ubuntu and LAMP. My app was a heavy database and an interface using php and ajax. I never experienced any problems with it and as far as I see, the solo wouldnt have problems either. Its not easy to tell without the actual code running.
There are several tools online to simulate traffic to your server and give a big workload on it, perhaps you could try one.