Knowing the subject aircraft type, and discipline helps.
In a tilt rotor, I would expect that at certain critical phases of flight, I would want the aircraft systems to take care of themselves, and only notify me when my action will be required to intervene with a decision the systems cannot make.
I do not want distractions at critical phases of flight. I most dislike having to divide my attention both inside and outside at the instant of lift off, to optimize engine power, when it should be able to optimize itself. Example of bad: AS355 helicopter, where just as you reach maximum power as you pick up, you have to have to look at the power indicator to match the engine powers to each other with a switch on the collective. Good: EC120, whose power display for it's single engine, graphically displays the percentage of the most critical engine limitation only.
Thus, I would like a tactile limitation marker, it would work as follows: As you apply power (be it the raising of the collective on a helicopter, or moving the power lever(s) on an airplane), a electric motor driven "bumper" which the pilot would feel at the point where the "system" regonizes the first limitation for that engine, would be motored to the limitation point. If the pilot needs more power, he/she can still pull/push past this tactile bumper and get it, but now you know that you're pulling too much, and it's gonna cost a lot! If there is a "5 minute" rating, it could start to time it at this moment. Maybe the control would have a subtle shaker to tell the pilot they are within a timed limitation. The display should show the relative power being demanded, and the position of the tactile stop at that moment. Interestingly, the Schweizer 300 helicopter has a very basic form of this, which is simply two fixed position rivets on the collective friction slide, you'll feel them if you pull through it to overboost the power, but you still can if you really need to.
Surley a sharp avionics guy can design a system where the sytem computer knows what the engine(s) are doing, how much additional power is available, and electrically drive a tactile stop to that point. The pilot will feel it, and can pull through, but has a sense of remaining within limitations, without looking inside at all. The DA 42 has somting like this for pitch limitation, though you cannot pull through it - it's just there!
The system can further assist the pilot by repositioning this tactile stop, in the case of an engine or other failure, which effects total power. In the case of exceeding a "5 minute" limitation, the tactile stop might be motoring back down below the presently set power. As it passes down, it will bump the control down, and the pilot would feel it. Again, maybe a small shaker. This would be accompanied by a display on the critcal power indication display, so the pilot can look at where things are. There are systems with tones for this, but we already have too many tones in the cockpit.
Presuming the tilt rotor has a height velocity curve (I'd sure be courious to see what it looks like!) I would like a computed indication of my phase of flight relative to the HV curve, for the prevailing contitions. Sort of like an angle of attack indicator for a fixed wing aircraft. Green is good, amber use caution, red - do you really want to be doing this? Again, no tones, just a very simple display, in the field of outside view. This display might also offer HIGE/HOGE information, when the airspeed drops below a certain value. (You can/cannot hover out of ground affect right now).
A tilt rotor has some very uncommon failure modes, and related pilot actions. Do you glide or autorotate? If you're gliding, can you turn it into an autorotation at the required moment, or do you smash off the rotors as you land horizontally. The avionics should be propmting these actions, and offering the tolerances available for a successful outcome.
Presuming that the display is offering some kind of terrain awareness, this must be easily disabled when desired. When in operation, the "system" should be constantly displaying as a moving, variable dimension cone, where the aircraft could be in the next minute with the power available (out climbing or out turning terrain or other hazards). The G 1000 does this in a simple way, in the mapping view - I like it!
If you can figure out how to build it, let me know, I'd love to fly it!