I agree with BigManTyrone.
Custom resolutions are vital.
I edit videos for Apple's AppStore and they only accept 1600x1200 or 1200x900 (plus their vertical versions).
I used to export from LumaFusion, then use VLC for the conversion. This is a huge pain, especially as the export seems to be 2 pixels off. I did not have that issue before, but with the latest Luma version (as of Dec 28th 2017), I am getting files with 1442x1080 instead of clean 1440x1080. The media information shows discrepancies between Resolution and Display Resolution. According to VLC one of both fields is always by 2px off. As a result I am no longer able to obtain the right pixel-perfect resolution for the AppStore ... I am still trying to troubleshoot this.
Long story short: having a custom resolution for projects and/or exports will help you support many use cases.
Thanks in advance.
I'm always curious to know what people are doing, their workflows, because that helps us make better software. For the most part we specify particular resolutions based on camera resolutions, but it seems like you are generating video from somewhere else. I want to understand that somewhere else.
Are there custom resolutions available yet? I work only in odd resolutions and aspect ratio. Just today I need to crop a 4k video with a 1100x1300 animation in the middle on iPad. I hesitated when I saw videos before buying.
Custom resolutions are incredibly important. There are so many odd canvas sizes I need. I remember when one tardo who wrote a book on FCPX when it first came out was trying to say how FCPX didn't need to add custom resolutions. For a good year it was having to make a custom project in Motion to have a custom resolution in FCPX. Yep, you had to buy a compositor in order to edit in a custom resolution.
For web work I often need to export to the ever changing social media post ratios (Facebook is constantly making weird sizes), and for ebook animations you are needing to often work all kinds of sizes.