Clicking "Use Custom Scale" then scroll all the way up to "User Defined" and you can enter your scale. There should be just another radio button and type in your scale.
I do this all day drawings, when its just one drawing its not a big deal, but when you have to change like 10 drawings a day with 3-4 views it gets really annoying.
Ben, you should submit this as an Enhancement Request. When you get the number post it here so others can vote for it and increase its likelihood of implementation.
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