IANAL, but here's the [awful] process I think you need to go through to now do a transfer from yourself, or an LLC to a trust. This is based upon my reading the CRS, section 18-12-112. What you do personally is up to you.
Doesn't matter if it's a pre-made SBR, it's a firearm transfer in the state's eyes. As a firearm, any transfer must go through a licensed dealer in order to get a background check done (correct me if I'm wrong here, but I believe it "must be on their books" for them to do a BGC for a transfer - you might have some wiggle room in the phrase "as if" that I highlighted in red, below). Also, a BGC must be performed for EVERYONE named in the trust (see the section in blue - "Not a natural person" is an LLC or a trust.
Because it must be transferred to the dealer, that's your first $200. Then they do a BGC on everyone in the trust, and then it gets transferred to you. That's another $200. At least each transfer doesn't take 18 months like in the old days, but that's a small victory after spending $400 to transfer something to yourself.
My biggest worry is if you do the transfer only via the ATF, you have provided in exquisite detail all the documentation needed for the state to prosecute you for an illegal firearm transfer. Open and shut.
...since you're asking for information, there it is. Don't shoot the messenger.
Applicable text from 18-12-112:
(1)
(a) On and after July 1, 2013, except as described in subsection (6) of this section, before any person who is not a licensed gun dealer, as defined in section 18-12-506 (6), transfers or attempts to transfer possession of a firearm to a transferee, he or she shall:
(I) Require that a background check, in accordance with section 24-33.5-424, C.R.S., be conducted of the prospective transferee; and
(II) Obtain approval of a transfer from the bureau after a background check has been requested by a licensed gun dealer, in accordance with section 24-33.5-424, C.R.S.
(b) As used in this section, unless the context requires otherwise, ?transferee? means a person who desires to receive or acquire a firearm from a transferor. If a transferee is not a natural person, then each natural person who is authorized by the transferee to possess the firearm after the transfer shall undergo a background check, as described in paragraph (a) of this subsection (1), before taking possession of the firearm.
(2)
(a) A prospective firearm transferor who is not a licensed gun dealer shall arrange for a licensed gun dealer to obtain the background check required by this section.
(b) A licensed gun dealer who obtains a background check on a prospective transferee shall record the transfer, as provided in section 18-12-402, and retain the records, as provided in section 18-12-403, in the same manner as when conducting a sale, rental, or exchange at retail. The licensed gun dealer shall comply with all state and federal laws, including 18 U.S.C. sec. 922, as if he or she were transferring the firearm from his or her inventory to the prospective transferee.
(c) A licensed gun dealer who obtains a background check for a prospective firearm transferor pursuant to this section shall provide the firearm transferor and transferee a copy of the results of the background check, including the bureau?s approval or disapproval of the transfer.
(d) A licensed gun dealer may charge a fee for services rendered pursuant to this section, which fee shall not exceed ten dollars.