I have not converted my home network to use split-brain yet and that's because I only just recently got Let's Encrypt to work with the DNS-01 challenge which verifies domain ownership via a TXT record. Now that the DNS-01 challenge works perfectly, I can use split-brain DNS to resolve my example.com requests to internal IP addresses. What I am currently doing is as follows and it is inefficient and ugly!

Local request ---> Internet --> VPS Proxy --> WireGuard tunnel --> Local Server --> WireGuard tunnel -> VPS Proxy -> Internet --> Local origin

Now that I have Let's Encrypt working using the DNS-01 challenge, there will be significantly less latency. It should look something like this:

Local request --> Local DNS Server --> Local Server --> Local request
                                         |
                                         --> Local Server --> WireGuard Tunnel --> Internet

I hope this is helpful! This will reduce the amount of locally generated traffic that must transit the VPN tunnel bi-directionally.