What's a better way?

1. Use the Super knob
2. Use the Modulation Wheel
3. Use an expression Pedal

Any of the above can be assigned to control the modulation depth. The first two require you to use your hand to do the work and the last one you can do with your foot.

https://www.yamahasynth.com/learn/modx/controller-box-switches-mastering-modx

So would I still turn on the Vibrato as an Insert in the Effects page?

If I use one of the above would that give me variable vibrato depth?

How do I assign the Insert to one of the controllers?

Just follow the steps in the article at the link I gave you.

The replies to one of your previous threads also tell you how to assign controllers.
https://www.yamahasynth.com/forum/unable-to-assign-fc1-fc2-or-pb-to-part-1

Thanks. I got it. Sounds GREAT! I used the Mod/Control and Control Assign to assign InsA PmDpth to my Mod Wheel. Works perfectly.

btw, good thing you checked my previous posts. Wouldn't want to accidently ask the same question twice or waste your time.

You aren't wasting any one's time. And this thread isn't the same issue you had before.

But Bad Mister and Jason provided a lot of detail in that previous thread and did a better job explaining things than I might have done.

The important thing is getting your problem solved - it doesn't really matter who does the explaining. Even if it was the same question it often helps to look at things from a different perspective.

Thanks again for your help!

If I really wanted to do what you originally asked for - an automatic delayed vibrato - then I'd use a Part LFO for that.

I think I started with the preset "Vintage Detuned". It already has a vibrato effect mapped to the mod wheel - but isn't the right speed (that can be changed) and also isn't what you asked for since it's not automatic. So I'm going to leave the mod wheel alone.

I edit the Part - navigate to "Mod/Control" -> "Part LFO" then:

1) Touch "Pan" which is the second destination. None of these destinations are used - so it doesn't matter which you pick. I just thought I wouldn't need two pan LFOs if I was to use the others. Changed "Pan" to "Pitch"
2) I changed the depth (for Pitch) from "0" to "73". This parameter will determine how wide the vibrato is.
3) Set "Speed" to 64. This parameter impacts how fast/slow the vibrato is.
4) Set "Delay" (under the waveform shape) to 65. This determines how much time the LFO waits to start after pressing a key. The "Key On Reset" is as the default "1st-On"
5) Set "Fade In" to 59. This will smooth out the beginning of the vibrato so it sounds more natural.
... left the LFO Wave as "Triangle", left loop "on", left tempo sync "off", left hold as "Hold", left fade out as 64, left all of the element depth ratios as 127.

You can also use a motion sequence to do the same kind of thing. It's not as simple so I'd probably not use it although it's available.

Not what you asked for exactly ...

When I listen to the record I notice that sometimes the vibrato doesn't happen after holding a note for a long time. Therefore, I probably wouldn't use a fixed delay. Since I have a Montage I'd make a vibrato happen (similar to the mod wheel in this Performance - but with the speed edited) and change the assignment from modwheel to aftertouch. This way the vibrato would only happen when I press down into the key allowing for me to determine the timing and if the vibrato happens or not. For MODX you could leave vibrato on the modwheel and edit the speed

This video shows a mod wheel being used after the key is held down.
https://youtu.be/Hv8srPUbJ0Y?t=24