You can do wallies at moderate speed but they definitely work better when you go faster. The key is to suck your knees up and over the object, if you don't your back truck is very likely to catch it or the board will just hit the obstacle and stay behind when you want to jam into the thing and then use the boost to bring it up and over with you.

Comparisons with manuals and ollies are both rather valid, having your weight mostly over the back truck will help you thrust the board forward and up the wall (which is why wallies out of manual feels natural), but your front wheels need to hit it first so in a way it's also really similar to a slappy. I think the timing also plays a major role, personally I wait until my nose is just about to bash into the obstacle to start lifting the wheels up and then I absorb the surface while jumping. Then the motion of riding up and over the object is very similar to ollies (you're trying to bring a skateboard up with you in both cases after all) except you never really hit the tail and let the object do the work (but don't forget to suck your knees up or it will claim your board in return).

Maybe find a block or a ledge where you can learn to just straight wallie up (maybe that's already what you actually mean you're trying when you specify 'wallies onto an object' though), it's a lot easier and safer then learning how to boost it over something at an angle and might help you figure out the timing. Those work exactly like basic ass wallride fakies except you clear the height of the thing and roll away on top. Then you can try tweaking the technique around the spots you'd like to do them at. Another good first step might be learning how to ollie up the thing with a deck check (pop into rock then push down on the nose to get the back truck up too) and then essentially practice the same move but in just one fluid motion - I feel like both maneuvers kind of walk a common line somewhere.

You're welcome and good luck, also since you're trying wallie straight onto the object arriving head-on, if you find yourself still struggling to figure out what you're supposed to do (although the knee tip is probably what you needed to visualize just that), maybe you could try picturing the obstacle as a super steep quarterpipe with vert (and no actual transition at the bottom, but you can imagine one that's not there) that you'd want to boost yourself onto the deck of. It's essentially the same technique, just taken to an extreme but soon enough you'll realize that most of the time, existing transition at the bottom of something vertical barely makes a difference once you've figured out the proper movement and timing. You just have to lean a bit further back because the impact is going to be a bit more brutal, so you need more 'room' to compress and absorb it (by thrusting the board in front of you) all the while riding up and over the thing without breaking momentum.

 You have to smash ur nose.  I do anyway. 

I've found that you also need to engage your upper body to start the weightless lift upwards with wallies, wallrides and nosejams to get any real height. Imagine an aggressive, kinetic energy being started with your upperbody, moving down through core and hips, but becoming weightless once you get to your calves and feet.

A whatllie?