I don´t know if a calculator would be possible to be included but I think this video is a good example of how final a layout could look.
Perhaps you should come into contact with the guy who made the mod. (more relevant if any future version is with a numpad)
Include a Countdown timer, I can already see it in front of me... dialing up the time and clicking it in to set it.
I'm going to get that keyboard from the GB and I am pretty familiar with writing QMK software (through the Massdrop CTRL). If the creator doesn't supply a calculator, I'll write you one. It's pretty easy and convenient, too. If you don't mind it being not scientific, it shouldn't take too long to write an implementation on QMK (and I could already prep it on the Massdrop CTRL, too).
I have a lot on my plate already, so I will let you write the calculator
The actual timer part of the countdown timer would also be not too hard, but making the UI on the OLED could be time consuming. Thank you so much for offering help! If you want to get a head start, feel free to DM me here or on discord - there is hardware available. I'd also love to give support and talk approach with you.
That being said:
While I wish I could personally support every feature suggested, I don't want people to underestimate the work that's already gone into this, and the additional work I already have planned.
No one has used the stm32f072 for the sort of features included here. A ton of work has gone into making this particular chip work with the OLED screen. Real Time Clock is a new thing that to my knowledge, no other GB keyboard has. Writing new views for the OLED screen takes a lot of time and thought. And no one has used the encoder with as many modes as are supported here.
Not to mention, all the work in VIA and QMK that has to be done. I'm constantly trying to add new things, focused mostly on easy configuration so that people don't have to be QMK experts or programmers to get the encoder to do what they want, change keymaps, etc.
I've pretty much selected the set of features I want to support - at this point, any other features won't really make the cut, and will have to be community implemented.
I think a lot of the features suggested here are interesting and good, but there's only so much time I have on top of my day job to work on this while still maintaining my sanity