When deploying the HAProxy VM as part of vSphere with Tanzu, customers have the option of deploying the HAProxy VM using either a 2-NIC or 3-NIC configuration. The default OVF Deployment Option is the 2-NIC design called "Default" and the 3-NIC design is called "Frontend".
From an Automation point of view, you can use either OVFTool or PowerCLI to automate the deployment. For a 2-NIC example, you can refer to my Automated vSphere with Tanzu Lab Deployment Script. However, for the 3-NIC example, a few folks were running into some issues when using PowerCLI for the automation.
The main issue is that because the default OVF Deployment Option is the 2-NIC design (Default), the two additional OVF properties frontend_ip and frontend_gateway is basically hidden when processing the OVF properties when PowerCLI.
Note: You can view these optional properties by running the following OVFTool command: ovftool --X:enableHiddenProperties vmware-haproxy-v0.1.8.ova
Even if you specified the "Frontend" OVF Deployment Option, PowerCLI does not seem to have the logic to retrieve the other optional parameters and hence can not be set as part of the initial deployment.