Just a Bill
No, I said "oh, brother," not "go hover."
The Complete Book of Cosmic Encounter wrote:
3. Regaining Lost Tokens: If you have any tokens in the
Warp or the Praw, you may either take one out from
the Warp and put it on any of your bases, or you may
raise one token from the Praw up to the Warp. If you
have no bases, you may release a token from the
Warp or the Praw into the cone. You may move a
token in one of these ways just before each of your
flips of the Destiny Pile. (If you are playing a game
without the Praw, you may regain a token only at the
start of each challenge.)
But mandatory is better; good change on FFG's part. Note that they also changed if from "before each destiny flip" to "once before you start flipping destiny". This is probably also a good change, in the event FFG produces anything similar to Mayfair's comets.