What to expect for ongoing Omnifocus support on High Sierra

My laptop is among those devices that will not receive future OS updates, starting with Mojave. So long as I continue with my current device, I will have to stay on High Sierra, which, as I understand it, will receive security updates from Apple until this time next year. OmniFocus is the only Mac-exclusive software that I use at this point and I am finding it difficult to justify paying a premium for new hardware that can be rendered obsolete at any time, based on the whims of Apple. I have many good reasons to move to Linux and I really want to do that but OmniFocus is so good, it has me hesitating. The balance that I’ve been able to achieve in life thanks to this app is worth a lot. There is nothing on Linux (or Windows for that matter) even close to OmniFocus. Still, if I’m going to spend the money to upgrade to OF3, I would like that investment to carry me through more than 12 months.

Given that, I am wondering what sort of support I should expect for OmniFocus 3 (and 2) on High Sierra going forward. If I continue to use my current device beyond the next 12 months, will OmniGroup continue to support their software on High Sierra even after Apple has abandoned the OS? I know it’s a pipe dream but it would be great if OmniGroup expanded to other platforms. Thanks!

Looking at the past few years, OmniFocus (perhaps all Omni apps) supports one OS version older than the latest. Which is to say that when macOS 10.14 is released, support for 10.12 will likely be dropped.