Actually I've mostly been using Gboard since I got the phone back. Neither Gboard nor Swiftkey has control keys as far as I can see, though. Thankfully, apps like Termux add their own control key functionality, but that obviously doesn't help with normal text input in e-mail or web browsers. Which is why I've started to try Hacker's keyboard again, but that has other limitations I'm not sure I want to put up with after having used Swiftkey and the current version of Gboard...