I have dug through the forums, I have tried every combination of every permutation on my own, I even tried the 2nd page of Google.
There doesn't seem to be anyone on this planet that knows what "Feature Type" does.
If a feature or option is not "Granted" it ceases to exist.

Here is what I want to do.
At level 9, there are two options.  Option A, and Option B.
If you choose Option A, then that's it.  The feature is done and over with.  It never comes up again.
If you choose Option B, then you get the additional option to choose a new language and additional language choices every 2 levels after that.

That's it.  It seemed simple in my head.

If I don't list both Option A and Option B as Granted, then they cease to be available as choices during leveling up.
If I try to use a hidden scapegoat feature to use as a pre-requisite anchor, it will give Option A as a choice every other level.
If I try to use level choices, you're forced to choose between A and B every time.
Sometimes B just disappears all together and never returns until I walk away from this mess and come back an hour later.
Sometimes the choose a language modifier isn't presented, sometimes it is.  It all seems to depend on what mood the system is in at any given time.

If I still had hair I'd be pulling it out.  At this point I'm just digging bloody holes into my scalp.  I've conquered Javascript for crying out loud.  Is this how I die?

Okay, here is the solution that would make all of this go away.

You must allow Feature Options inside the current class feature to exist in the prerequisite list of subsequent Feature Options.

For instance, you have 4 feature options in one class feature:
Option A
Option B
Option 1.b
Option 2.b

This way, Option 1.b and Option 2.b will only be available if Option B is chosen.

I'm not crazy after all, this is a short-sight in the tool and should be update to work as such.

I have explained this multiple times, so your research was incomplete. The vast majority of features are “granted.” “Optional” and “Replacement” features are for the types of stuff from Tasha’s Cauldron.

A “Class Feature Option” has nothing to do with an “Optional Class Feature.”

You would need to create a “Granted” feature at 9th level that has two Options available and the ability to pick one of them. You would then need to create "Granted” features at 11th, 13th, 15th, 17th, and 19th levels that would do absolutely nothing except have an Option that is “granted” with your 9th-level Option B as the prerequisite, and they would all have:
Modifier: Proficiency->Subtype: Choose a Language.

The issues are that those 11th-19th level features would always be visible to everyone but wouldn’t do anything. Add to that the issue that the “choose a whatever” Modifier Subtype doesn’t like to be attached to a class feature Option.

I explained about Options and Prerequisites in more detail here:

https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/67361-subclass-help#c4

I hope that helps.