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 go?
AAll files get added to a folder on your device named Igloo which is accessible via the Files app (On my iPhone/iPad -> Igloo -> Downloads), or Finder on a macOS device with your iPhone/iPad plugged in.

If you don't see the folder, restarting Igloo, then the Files app, then your phone as a last resort should make it appear.
QHow do I use the custom uploader?
AIf you're a developer, the options in Igloo settings should be obvious enough for you to make your own or use something that already exists. If you're not, you can use this minimal upload script.
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. Although it states it's not, it clearly is a page of endorsements. Igloo was removed for its creator defending himself against a toxic IRCv3 member. However, Igloo supports the following extensions: