This idea is most likely completely unrealistic, however, it would be a very powerful tool.

When you place a a hollow fuelselage, you could make it so it can make a cut from another piece of fuelselage. Let's say you have a 2x2x2 cube, and you want a circular hole straight through the middle, as of right now, you could spend hours making it look right, but if you could take a hollow fuelselage and have it run through the middle, cutting, or making any piece of fuelselage that intersects with the interior of the hollow fuelselage invisible, you could make holes significantly easier.
Other uses include making bomb bays. Being able to place the hollow fuelselage and select a "cut away" Option on the part edit menu could make a cut the size you want perfectly in your plane.
The use case that made me think of this was a VTOL system similar to the F-35. Making a circular cut out straight through the middle of the plane would allow you to place those lift fans visible in the middle of your plane.
I'm aware the idea of a bomb bays fuelselage is a popular one among the community, but this would be a simpler option, with more versatility.
Thank you for reading.

Since the indestructible glass glitch doesn't work anymore, there's no way of protecting your vehicle or plane from enemies.
Of course, it's not going to be indestructible, here's my idea:

The Armour piece is modifiable just like the fuselage piece. It should have a "Toughness" slider, where you can choose how many rounds it can withstand. But we have both cannons and machine guns, so I think that if you choose the armour to withstand 1 cannon round, we should multiply that by 1000,having it withstand 1 cannon round but 1000 machine gun rounds. If you chose it to withstand 2 cannon rounds, 2 cannon roundsx1000=2000 machine gun rounds. when the armour block is hit by, for example 1 round when it's set to withstand one, it would be better to have it absorb the first but get penetrated by the second one,so on, like:

Set strength :3 round/s (can actually withstand 4 rounds, because 3 destroy the armour but don't penetrate but the 4th, not having anything in the way, penetrates)
It would also be nice too have a "Armour broken" text appear when the armour is, in fact, broken.
I might be asking too much so decide if you want to add this part if you will ever add the armour.
The armour could ricochet bullets if they're fired at a certain angle or the armour is steep,and a text saying "Ricochet" for the attacker and "Bullet Ricocheted" for the attacked

1. add village and city yes the map of sp is really empty so maybe you can add more stuff like house, train station, thicc and tall buildng, farm.

2.easter egg.

3.AI, yes the ai is really stupid sometimes even doing this like putting gear down 10 feet above runway, do an nosedie.

4.walking,we can walk around the plane

5.performance improvements, i mean my phone can hndle a game that have so many detail and i got 60 to 20 fps in that game, but in sp i only get only 1 to 40 fps.

6.instrument, we need instrument its really help8ng flying

1. done

Plz add multiplayer to the game, it would attract more players and we would be able to show off our creations, the community has been asking for this for quite a while, now plz, fulfill the hunger for multiplayer, the part limit on mobile servers would be about 200 parts, and the player limit could be chosen by the room manager, from 2 to 20 people, we could have contests with each other... we could dogfight and have battles in general... or just straight up fly around and hang out, plz, I strongly suggest this to you, it will really benefit you jundroo dev's and us players will be far happier, plz add multiplayer