I would like to see the persimmon tree.

I think that if a hypothetical fourth installment were to be made, it would require a complete 180-degree shift in the personalities of the key characters. Many of them probably wouldn't fit into the plot, and they would be turned into cardboard cutouts. The film would be crammed with a bunch of unnecessary new characters and plot arcs that last for only three minutes, because they need to sell more toys. And in the end, they would just ruin Woody, because Buzz would have been ruined earlier in the process. Overall, the film would be like a reversed third part, with a conclusion that is diametrically opposed to what was in the ending of this wonderful trilogy. And I doubt they would make a fifth part; instead, they would probably make an alternate version in which Buzz is a living, real person, like a remake of that spin-off from the early 2000s. And that's all I can say about it, except that it sounds strange enough to make me lose interest right away, despite my love for space themes.