Not all borrowers are present at same time at signing
All GoDocs documents, including the security instrument, are fully configured to support execution in counterparts. As such, for concurrent signing that is at separate times/locations, you can have one person sign their version and then have the other party sign their version. If the parties sign any document in several counterparts, each will be deemed an original but all counterparts together will constitute one instrument.
Execution by counterpart is widely accepted as a valid way to execute loan docs, and is enforceable as long as language permitting it, is included in the document so signed -- ours include such language. That is referenced throughout our loan documents, as per the screenshots below:

At Lender's discretion and determination, the separate packages can be used collectively, or you can include all signed pages in one package.
Otherwise you can also have one party sign first and then send the party-1 signed package to the next party so they can sign the same version.
Additionally, we intentionally include acknowledgments as separate pages following each document where an acknowledgment is required or is otherwise marketed to be included. When a document is executed in counterparts, the specific acknowledgment will note who the signer was that appeared before the notary public to execute that certain document. We have never experienced pushback from a title company or outside counsel on this practice to date. That said, if your title partner or legal counsel prefers a specific format, please let us know, and we would be happy to explore how we can support that.