PlanetsCentral

Hi again

the following is long and I'm not sure it's something you are interested in. So use it as you will. But it would be nice to tell me, because in case you are not interested in detailed proposals as below at all, it would be less bothersome for both of us if I simply don't give them in the first place.

Oh yeah, and anyway the priority is quite low too. Naturally.

PCC always does that. It wants to prevent you from accidentally burning too much fuel. Again, it's hard to decide what is accidental and what is intentional.

Well yes and no. I was able to reproduce this with interuniversals (tech lvl 8 but engine lvl 7!) and warp9 which PCC didn't set. It stuck to w8.
Still it's unintuive in my oppinion. Though there is more. I agree that it is hard to decide wether some effect is accidental or intended. So simply don't do so. There is no need.

That's why this is somehow illogical:

'NAL' is clear, leaving the ship fuel-less sounds like a mistake you'll fix up.

You tell me filling a merlin with supplies but no fuel and in succession failing to tow it to the intended waypoint (because PCC calculated too few fuel to be used) is intentional? That's hard to believe. But anyway there is an easy way around it at least in case of the Merlin. Don't try to read what's intended but stick to the orders you have. The order is to reach the Waypoint X with the towing ship S. But since the Merlin to be towed doesn't have fuel for alchemy the conversion will fail. No Problem here. But if S doesn't have enough fuel to reach it's waypoint there is but one way to show this: give the real fuel consumption and mark it red as usual. There is simply no way around there.
PCC MUST tell me what will happen, and not what I might have planned to happen.

So for the stated cases I would mark the Ship screen as follows (in addition to the checks you already have). Ship screen for Merlin with loaded supplies:
If the FC is NAL there would be no need for fuel aside from movement. So no changes here.
If the FC is something else but there is no fuel (and no waypoint set) the fuel-estimation should turn yellow but still show '0' which is the right number for no movement.
If there is a waypoint set but there is not enough fuel the fuel-display should turn red as usual in defiance of any other possible fails.

Shipscreen for any ship towing such a Merlin:
First the fuel consumption should be calculated with the total mass the Merlin would have in the movement phase with the current settings not regarding possible NE which I may or may not add to the Merlin later on.
Second if the calculations show not enough fuel to reach the waypoint this is a serious red. There is no way around. Orders will fail and that's it. IF and really IF I intend to let this fail then I am obviously an advanced player and I do know what I'm doing perfectly well. So displaying the fuel consumption in red wouldn't hurt. But it will hurt if you mark it green and show lesser fuel than actually needed.
Third you may or may not mark the fuel consumption yellow if there is enough fuel to reach the waypoint even without alchemy, but the Merlin isn't using NAL but simply doesn't have fuel. Though I wouldn't. Because this is a problem with the Merlin and not with the towing ship. So it's got nothing to do with this ship.

Last but not least there is that multi-turn issue. Frankly I don't get why lvl7 engines do use warp8 automatically but lvl1 engines don't use w2 even if there is no real distance and fuel consumption is not noteworthy. This means PCC is "too" intelligent. But I think this will pretty sure fail if some game uses alternative engine defines. I would prefer a simple rule here, something that I can learn from using PCC but without looking into the code. So no "hidden" checks with even more hidden parameters.
Knowing you you'll probably prefer your solution. And I agree that it's not too bad at all (as long as you use standart shiplists). In that case I would make two suggestions for the display without doing any real changes to what PCC is doing. First if PCC sets a speed/waypoint combination (including warp 9/further than 81ly away) which results in multiturn movement then simply display the ETA (Reisezeit) in yellow. That way you'll be able to notice an unexpected multiturn movement more easily. Second if I manually set the speed to something PCC regards as 'overdrive' of the engine type (as in the example above) then mark the warpspeed in yellow as well. This gives a strong hint to why PCC decided to choose a lower speed priviously.

So far my 10 cents.