Can git commit signing implementation be updated to be easier to use?

Been trying to implement signing of commits in a project we use.
I have sort of gotten it to work but the implementation between a none signed commit and signed commit differs a lot and i would like it to become much easier so the code in the project i use gets cleaner.

Basically this is how we implemented none signed today, it works for a newly created bare repo also.

oid = repo.write("This is a blob.", :blob)
index = repo.index
index.read_tree(repo.head.target.tree)
index.add(:path => "README.md", :oid => oid, :mode => 0100644)

options = {}
options[:tree] = index.write_tree(repo)

options[:author] = { :email => "testuser@github.com", :name => 'Test Author', :time => Time.now }
options[:committer] = { :email => "testuser@github.com", :name => 'Test Author', :time => Time.now }
options[:message] ||= "Making a commit via Rugged!"
options[:parents] = repo.empty? ? [] : [ repo.head.target ].compact
options[:update_ref] = 'HEAD'

@commitref = Rugged::Commit.create(repo, options)

index.write

But to make signed commits in a new bare repo the first part is the same with options but alot after differs.

oid = repo.write("This is a blob.", :blob)
index = repo.index
index.read_tree(repo.head.target.tree)
index.add(:path => "README.md", :oid => oid, :mode => 0100644)

options = {}
options[:tree] = index.write_tree(repo)

options[:author] = { :email => "testuser@github.com", :name => 'Test Author', :time => Time.now }
options[:committer] = { :email => "testuser@github.com", :name => 'Test Author', :time => Time.now }
options[:message] ||= "Making a commit via Rugged!"
options[:parents] = repo.empty? ? [] : [ repo.head.target ].compact
options[:update_ref] = 'HEAD'

# Create a string of the contents to be commited.
content = Rugged::Commit.create_to_s(repo, options)

# Sign the string.
crypto = GPGME::Crypto.new(armor: true)
signature = crypto.detach_sign(content, signers: @cfg.sign_key).to_s.strip

# Create a commit using the string and signature. 
@commitref = Rugged::Commit.create_with_signature(repo, content, signature, 'gpgsig')

# After doing this create_with_signature calling for index.write does not work.
# and i have to do this repo references else i cant see any commits when i do git log --show-signature

# Check if HEAD exists and handle accordingly
if repo.references.exist?("HEAD") && !repo.head_unborn?
  # HEAD exists and points to a real branch
  repo.references.update(repo.head.name, @commitref)
else
  # HEAD doesn't exist or is unborn - create default branch
  repo.references.create("refs/heads/master", @commitref)
end

I would like the implementation of signed commits to be as easy as doing a normal commit just that i have to specify the key i want to sign with.
e.g

# Just want a function i can call for as easy as Commit.create that signs my commits and update the reference on disk. 
Rugged::Commit.commit_with_signature(repo, options, signature)

Start by reading Rugged::Commit.create, create_to_s, and create_with_signature, then trace how index.write and reference updates behave for a new bare repository. Done means a signed commit can be created through one Commit-level call with the signing input while preserving normal index and HEAD/reference behavior.