Super-niche use case but here goes: There are channels I like that have no guide data and it offends my visual aesthetic to look at a gaping hole in my guide. With a lot of help from @kanipek - I've come up with something that works well. You can customize this to your liking and use it as an XML source.
<?xml version="1.0" encoding="utf-8"?>
<tv date="1/1/2021 12:00:00 PM" source-info-url="" source-info-name="" generator-info-name="" generator-info-url="">
<channel id="NAME OF YOUR CHANNEL HERE">
<display-name>NAME OF YOUR CHANNEL HERE</display-name>
</channel>
<programme channel="NAME OF YOUR CHANNEL HERE" start="20210101000000 +0000" stop="20211231235900 +0000">
<title>CHANNEL TITLE HERE</title>
<desc>CHANNEL DESCRIPTION HERE</desc>
<sub-title>CHANNEL SUB TITLE HERE</sub-title>
</programme>
</tv>
What you're doing here is 1) defining a channel in the <channel id=>
area and then creating program information in the <programme channel=>
area. In this case, we're creating a single show that is 365 days long. You'll have to update the start
and stop
times come January of 2022.
Save it as whatever you want .xml and import and map channels as desired.
There's obviously a lot more that can be done with an XML guide but what I needed was something lean to just populate my grid guide and this did the trick. Hope it helps someone else.