Thanks. Granted paid hosting is obviously better than free hosting in terms of what works and doesn't - but like you say, I feel like I'm wrong for not buying something that's optional to start with... I've seen plenty of VAs using infinityfree under free hosting with no issue (though I don't know what ACARS client they use). I am relatively new to phpVMS and the VA scene, and, like I mentioned before, spending money on something that I don't like or won't work isn't viable for me at this stage.
On your other point, I've allowed CCFTracker through my firewall, with no effect. I still believe that this issue originates in the Module, rather than the client.b