Looking for a way to escape period for yaml params that have dots in them

[hferguson]

Please describe your feature request.
A clear and concise description of what the request is and what it would solve.
I would like to use yq to inject a parameter with dots and slashes in it. For example, I would like to represent the following which is an ingress annotation for helm:

globals: ingressAnnotations: cert-manager.io/cluster-issuer: letsencrypt

I tried appending this to my yaml file by using
yq -i '.globals.ingressAnnotations.certmanager.io/cluster-issuer="letsencrypt"' values.yaml
and this resulted in
globals: ingressAnnotations: cert-manager: io/cert-manager: letsencrypt
Maybe this exists already, but is there a way to escape dots so they aren't treated as delimiters? I already tried escaping the dot with a slash i.e. "cert-manager.io" but that only gave me the slash

The use case why I would do this has to do with OpenText Corporation's helm chart for Content Server deployments where you get the chart with a default values.yaml and you add/update by passing parameters to your helm install call