Great work done here on getting it this far. I was just about to start using it, but similar to Xandrios I also ended up having questions about privacy. I didn't see clearly, but it seems you have moved to storage on your own back end now? If so, how is the data we're uploading being secured? There is a lot of sensitive information in the data you host, so having it be encrypted would be best. Not sure what database you're using, but ideally something that can let you have row-level encryption. Without that, even for a hobby project, if this data gets stolen you're opening yourself up to a lot of potential hurt.

Edit: Some more thoughts:

• Right now you are importing the PDF, which gives you airport pairs, miles and XP earned. You could work with these to figure out class of travel, and the cost of ticket.
• You should ask the user since when they have the current status, so that you could work out PFL as well, if needed.
• Calculation of XPs and UXPs seems strange. This might be because the qualification date for Platinum needs to be separated from qualification date for Ultimate. In my case, neither work correctly.