What kind of Japanese maple is it? That can make a real difference in its typical growth habit and how you may be able to protect it from deer down the road.

Just off the cuff, I don't think what you propose is going to have much value. Without seeing the tree or knowing the variety this is all speculation but the tree sounds like it might be a smaller variety, perhaps even a weeping form. In which case, staking the branches upward is not going to produce the result you intend.

Just a word or two on growth habits....... you can stake lower branches to a more upright position but it will greatly affect the beauty of the tree, which is to grow uninhibited in the form nature intended. And they will likely never be really vertical or ever above the reach of a hungry deer. Tree branches never grow higher on the tree than where they emerge initially - it is the trunk that elongates vertically. A better choice might be to remove lower reaching branches but with a 4' tree, that is somewhat of a moot point as well.

You are going to be far better served by fencing the tree away from the deer predation or by using a deer repellant on a routine basis