This plugin seems to have started out well, but gone down hill around 2 years ago.
There is no error handling in the email sending, at all. None.
There is no logging. Anywhere.
Emails fail to send, with no notification and no way to audit them.
The email sending relies on WP-Cron - no state reporting flag is passed to the scheduler instruction, and these can fail, also silently.
Some functions will call additional functions directly, some rely on filters, and in many cases, these mixed standards happen on consecutive lines.
Variable naming is inconsistent, which makes it all the harder to debug when (not if, WHEN) you find problems.
Many of these issues are simply careless programming and I can only assume result from inadequate testing.
Functions which return a bool will run an if clause on a variable - if it is equal to 1, return true, if 0, return false. This shows a basic lack of understanding as to how PHP works, which for me rings alarm bells in a plugin responsible for organising bookings and taking payments.
Then there are the irritations - if you set a total count for all tickets in an event, you still get individual totals against each type.
The "Register" button on the purchase form shows "Register" until you select a ticket, then it shows "Proceed to PayPal" - why not hide it? It's not hard.
There are so many corners cut, and I do not trust it, at all.
I have lost weeks on this plugin, trying to diagnose lost tickets, lost emails and missing bookings.
If you intent to process payments for your events, DO NOT USE this plugin.
It is not reliable enough, and if you are not a programmer with a decent understanding of how booking and payment processing systems should work, you will struggle to make this work reliably.
Also, why do the support team need admin access to my site when I have sent reproduction steps with images and full instructions? It's absurd to even ask!