FE Hoppy
Is "Hoppy" the same as "Skippy" ? .. if so, g'day ..
First, I am envious - really and truly, I am - obviously you have a most wonderful answer to an older young chap's desires for get up and go - even if a lot more expensive than Sildenafil - and, no, I have yet to contemplate seeing things in shades of whatever colour is reported to be the side effect. Closest in my background was an empty Electra on a cold night and with nothing better to do ...
(a) Without having a look at your AFM with chin in one hand and a pencil in the other, the following suggestion might not be appropriate. However, my initial line of enquiry would go along this pathway for a simple solution -
(i) prepare separate general takeoff charts for accel stop, separates/composite for takeoff distance (although I would expect the AEO case to be convincingly limiting), and gradient charts for BRW/V2. You probably have such animals in your company Ops Manual performance volume at present.
(ii) using whatever level of equivalent temp derate you desire (and it must be a wonderfully terrifying experience if you go full grunt in these circumstances) note the limit RTOW from your individual runway chart.
(iii) use the general charts to figure the nominal accel stop and takeoff distances for this weight, and the gradient capability at the scheduled V speeds.
(iv) use the general charts to figure the lowest V1 which will not cause you to exceed the above distance figures for your BRW, with a suitable V2 to achieve not less than the scheduled V2's gradient capability.
(v) schedule a V1 somewhere between the two limiting values according to your horoscope's recommendations for the day.
What this approach achieves is to make sure that
(i) the modified takeoff gets to a similar point down the runway at 35 ft when compared to normal chart data.
(ii) the subsequent climb is not inferior to that scheduled normally, so that you don't have to worry about obstacles. This probably isn't going to be limiting at all.
(iii) you know how many miles of pad you have for the accel stop.
Given the impressive T/W for such a takeoff, I probably wouldn't be too worried about Vmcg - you would be well and truly through the region by the time the aircraft realised it had suffered a failure. Then again, you have a wide range of available V1 figures - so you can pays your money and takes your chances according to your philosophical preferences.
I wouldn't fancy using needlessly high V1 and Vr figures if the bird has a desire to skate.
(PS .. I quote very reasonably for this sort of work ......and a discount would accrue, depending on how many rides I can come along on for the experience)