I just found something that solves both yours and my dilemma. I found it purely by accident. I thought my items poofed and then I figured it out. Let me explain:
I never knew this was there before but if you click esc, there's an option under vault: enable auto deposit/transfer (check it)
By checking this field, all you have to do to deposit items is shift-click. It will deposit the items into the last field selected under the deposit tab.
So like in my case, running my warlock, I set it to caster (in the deposit tab) and go back to the withdrawal tab
As I go along in a climb, all I have to do is change the level field and take out what I want and shift-click the items to deposit
There's no switching tabs. Just withdrawal and shift-click to deposit.
It doesn't resize the inventory (Which is good for me cuz I swear Im going to kill my "I" button)
I dont have to keep resetting the category to caster, just change the level range as I go along and ctrl-click (out of vault) and shift-click (into vault)
Im in absolute amazement. Like I just found out about sliced bread or something
Here's the downside (How I found out)
If you glyph, normally you shift-click to bring up your glyphable in the glyphing box. If your vault is open, it will deposit it in the last field selected in the deposit tab. So, you have to manually drag it over (or deselect the check box in options), or close your vault. Same for fish I imagine, when you shift-click the fishing pole you wanna use