HI Kotten_3,
The cleanest way would be to split it in three parts. See image below.
https://www.amazon.com/clouddrive/share/fcf2spEVJgvoFeSAopLpjrE9Wfs4hC9j9blGKt0qevA?ref_=cd_ph_share_link_copy
Green, red and then blue would be “my” sequence. Perhaps the red one shorter and the green one longer, to cut in the bow for a simpler animation. Test the Splines> I-Profile for the red, it has all parameters in the L shape to do so.
The Scene file:
https://www.amazon.com/clouddrive/share/4AQ4oGny17NtJVohOZtKLuSiQkJdGLzl5iza7kxw5OC?ref_=cd_ph_share_link_copy
Create three copies. Follow the way it should be written. Perhaps use pen&paper; first. (Of course, In Illustrator that could be done much faster…)
Set the splines to Close Spline> None.
Deactivate the two others each time.
Delete the points the specific spline doesn’t need.
Adjust perhaps with the handles the shape.
Use the Sequence up and down (select the “segment” if you have more than one segment in a shape)
Holes can be closes with the Joint Segments, delete again what is not needed.
The second and the third stroke will create a “bleeding” of the fresh ink in the corners, which marks the crossing of two lines, and the double amount of ink, so it will be added while crossing, or with a PLA [point level animation], based on the realism you like to have.
Close the splines of course and then use the Spline Mask or the Boole, what ever gives you the best workflow or results. Note that the Spline Mask will keep the Bevels, whereby the Boole will have a hard cut on the current end position while “drawing.
Example of a possible animation:
https://www.amazon.com/clouddrive/share/vxCkH1PaTqyrKHCkvLcGqX5T2Ymaul9NdbPVMFKOctu?ref_=cd_ph_share_link_copy
There are two files in this link. The file _11 shows an example, and file _12 shows the same animation, but stored in an Animation Clip. Note that there are two clips, and both can have a Spline-Editor based progress. I think the Animation Clip seems to be idea for such multi channel animation.
All the best