On any character of iether faction I go to the mailbox and create a new mail message.
I address the message to myself "@zakon90505".
I make the subject of the message the type of Doffs that I am going to put in the message.
I load up the Doffs into the message and send it.
Now I can go to any character on my account, iether faction, and grab the appropriate Doffs as needed for fleet projects without clogging my Doff rosters. KDF Doffs can be used in Fed projects and vice versa. I can sort by Doff type because I put that in the subject line of the mail message (this is a sortable tab).
I hope some of you found this helpful.