Does the health check function of Spring Cloud LoadBalancer support 4-layer connectivity checks?

Is your feature request related to a problem? Please describe.
In my request, I would like to check the connectivity of the 4th layer of the service, without considering the connectivity of the 7th layer. I would like to know if it is currently supported? I examined the source code and found that currently only 7-layer connectivity is available. I understand that for a microservice framework, 7-layer checks are normal. However, my current requirement is actually to only check 4 layers because I don't know if the upper services have check interfaces, and even the upstream might not be a microservice application. Therefore, I want to perform 4-layer checks. How should I modify it?

Describe the solution you'd like
I want to know how I should modify the source code to rewrite the health check without any risks.

Describe alternatives you've considered
Can TCP layer 4 inspection be supported?

No files or tests are named. Start by locating the existing Spring Cloud LoadBalancer health-check entry point and tracing the current 7-layer connectivity check. Done means the TCP layer-4 support question has a documented, tested approach that explains expected behavior and risks.