You cannot expect flawless homogeneous surface, even color distribution and same weather resistance you might know from products made from chrome tanned leather. The vegetable tanning process imparts typical natural characteristics, which makes each leather piece unique. There might be small marks from insect bites or scars on the leather surface which are not hidden under thick layers of pigmented paint and it will change its gorgeous patina over time getting slightly darker. This happens due to exposure to sunlight, oxygen, humidity and oils from your skin or products you might be using to make it more repellent to water. The natural oils of wax will provide more protection, but do not close the pores completely, leaving the breathable properties. You can still use coating isolation sprays, but you must be aware, that you are alterating the aging and tangible properties of those natural product. If the product gets wet, let it dry naturally and take care of it afterwards, using some wax or oil.