Help, I need to get latest vitals and age to use them on a custom document template

Situation
I am doing a document template that is a custom report, it gets data from many LBF forms, some DEM and HIS fields as well.
But I don’t know how to get patient’s latest vital (weight and BMI).

Any advise? I believe I have to update download_template.php (/interface/patient_file/download_template.php), maybe add some additional substitutions on doSubs for example {PatientAge}{VIT:latestWeight} {VIT:BMI}.
I know PatientAge can be calculated based on todays date and DOB, maybe we can record patientAge in vitals, that way we can track vitals as a timeseries related to its patient.
There is another code that may help (here it is calculated patientAge) interface/forms/vitals/report.php this may help to solve this need, but I don’t know how to?

OpenEMR Version
I’m using OpenEMR version 7.0.1

Browser:
I’m using: Chrome

Operating System
I’m using: Ubuntu 22.04

Search
Did you search the forum for similar questions? Yes!

Logs
Did you check the logs?
Was there anything pertinent in them?
Please paste them here (surround with three backticks (```) for readability.
You can also turn on User Debugging under Administration->Globals->Logging User Debugging Options=>All