The In Duration will never be longer than 40% of the length of the Title in the storyline.
There is a "1 second" span of time in which the text is "normal" and no animations occur, then the Out sequence starts. This is where the problem with this title happens. The Out Duration parameter supposedly sets the number of frames (duration) that the End effect takes to execute. Anything less than 60 (or, 100% of the sequence if you will) will shorten the overall length of the title.
*If you need to match the end of the animation to a specific frame in your storyline, you can set a marker at the point the out duration literally ends, then stretch the title to match the marker's position with the frame you need to end the animation on. Be aware that any stretching you do to the title will also lengthen the duration of the out effect because the Title itself is designed as 150 29.97/fps template. All internal values will be stretched or compressed according to how the title is applied in the storyline.
So the Out Duration starts at about the 60% mark in the template, and the length of duration is displayed as # of frames from that starting location to the end of animation. Like I said, anything < 100% (60) will shorten the title's apparent length.
This title is called Custom because you can build quite a number of different customized effects without having to go into Motion. A Basic Title with transitions would be much harder to accomplish. There is so much more you can do with this than simple fade in/fade out effects.
A couple of years ago, a similar issue came up (https://discussions.apple.com/thread/250514512?answerId=250982088022#250982088022). I remade the Custom title so that the End of animation always ends at 100% and you have the option to have all the start and/or end animations last the entire length of the title. You can download a copy here:
https://fcpxtemplates.com/ngtopics/CustomTitleCopy.zip
If you need them, here are Installation Instructions.
I'm not sure that it will make complete sense in this context, but here's a recap of the instructions I wrote previously:
The only changes to this list an the original's is: In End Offset % and Out Start Offset % replace In Duration and Out Duration. Both are technically off by default. This Title does nothing by default (same as the original).
The major change between my version and the original: the Sequencing operations exist for the entire length of the Title (the original was split -- Sequencing In and Sequencing Out with a "dead zone" in the middle).
To have Text fade in at the beginning:
Set the In Opacity to 0%.
Set the In End Offset % to some value > 0. 20% of a 5 second Title is about 1 second. If you stretch out the title for a longer effect, you might want to scale that back a little.
Set the In Spread to about 100 if you want all the characters to fade in at once.
To have Text Expand from the beginning:
Set the Out Tracking to a larger number. You can go beyond the Slider restriction of 100% by clicking on the number value and dragging up to increase it as high as you need.
Set the Out Start Offset % to 0. That will start the animation from the beginning of the Title.
Set the Out Spread to a large number*.
[Due to the crossing over of two similar behaviors, the Out Spread needs to be a little excessive in order to overcome the effect of the In Spread. To find the best value, set the playhead to a position where you can still see the first and last characters as they are expanding and adjust the value until they stop moving.]
To apply a fade out at the end, you do not want to set the Out Opacity to 0 as this will animate the entire length of the title effect. Move the playhead to about 1 second before the end, and set a keyframe. Move the playhead to a frame or two before the end and move the Out Opacity slider to 0. This animation will work just as well as long as there is an Out Start Offset % less than 100%. (At 100%, not even keyframed parameters will work in this effect because they won't have any time allocated to animate... if you get what I mean.) You can alternately set a fade out with the Video Animation editor which will always work.
If you have any questions about Custom copy, get back to me and I'll try to answer them for you.
Hope it helps...