I've got Tam's A-4, I have a Supersport in it at 18.5 pounds of thrust at nearly the same weight and size as a P-60 but with a little less fuel burn. I put in an extra 12 ounces of fuel in the form of a header tank between the saddle tanks, and have my timer set for 7 minutes. I usually shut down with 10 minutes run time including start and taxi (on a taxi tank) and I land after the 7 min timer goes off and have at least 15 ounces left before the UAT, many times a lot more. I can swap out my header tank for a smoke tank but I haven't, I like the extra flight time I get while still having a lot of loiter time if I need it. I fly full throttle a whole lot and the jet moves with a Supersport, it's really fun - but I do limit the heavy G loading. As far as keeping the speed up, I can't really say I go faster than I need to in the pattern. I did at first but then I flew one of Tam's A-4's powered by an EDF and realized that I was being far too chicken on my extra speed added when landing. What the A-4 needs above all else is respect for rough handling at any speed, and also a good CG check. Tam's CG is slightly further aft than his manual, (call him up and speak to him directly on this as I don't want to put something down on print that isn't right). If you yank the sticks around heavily like it's a trainer, it will bite. But it will land very slowly when you get used to it. Just don't yank it around... fly smooth. And I also use a little bit of top rudder in turns and have not felt the dreaded "tuck under" as long as the jet is flown smoothly. I think the A-4 will tuck in heavy G, (hard pulling) as the wing begins to blank the tail out in turbulence, and then the natural tendency is to loose pitch authority. As this usually occurs in turns, the thought is that the nose "tucks" in a turn but it's like saying a cough will kill you when in fact it's the "smoke" that will. The "smoke" is the heavy G handling and not respecting the modified delta wing's tendency to blank out the tail. And, also, I believe it's the lightening quick roll, and over controlling roll with too much bank in turns by accidental over shoot and then too much G trying to maintain altitude. To recover, relax elevator, roll wings level and gently pull out of the descent. Then to avoid doing it again, just give the girl a little more room to make her moves. She can give you a false sense of security because the roll is lightening quick with no problems but the pitch should be "applied" more gracefully.

That brings up another point. Radio setup and expo can be a friend or enemy. Call Tam again and see what he's using, it's easy to have too much juice in the ailerons on this jet.

My A-4 weighs a hair less than 18 pounds dry + UAT. I have the heavy turbine version but I lightened up the airframe in some areas and beefed up the airframe in others. I have absolutely no lead in it, I moved everything as far forward as possible, even the engine, as I modified the ducts and mount to bring the engine forward several inches to balance with no lead in the nose.

You can tell if you have the EDF version (light weight) if your wing roots and other parts of the airframe have lightening holes in them. There are other areas that are different but those are the easiest to see.

PS - the pic of the nose area just shows how much can be stuffed in there if you make the shelf attach to the airframe and not the nose cone. Also, I'm not using Tygon for the fuel pump feed, that was just for initial setup as I have a hard plastic fuel line between the UAT and pump.