QCan I make Igloo run in the background longer?
AUnfortunately, no. This 3 minute limit (now 30 second limit on iOS 13) is something Apple put in place and there is no reliable way to get around it on our end; however, there are a few things that you can do.

Jailbroken: Use tweaks such as Watchdog or Dissident.

Non-Jailbroken: Setup a bouncer such as ZNC and use our push module.

You can also complain to Apple.
QWhere do files received via DCC/XDCC go?
AAll files get added to a folder called Igloo in iCloud Drive. This folder can be accessed from all your Apple devices.
QWhy is Igloo not on the IRCv3 client support table and what caps do you support?
AApparently that page isn't just a technical spec page (though it should be), and Igloo was removed for its creator "insulting" an IRCv3 member. However, Igloo supports the following extensions: