“Substitute Into”: I am not sure if I understand correctly. What I frequently do is for example: subs((2),(1)). Here I do not need to attribute a name to (1) in order to substitute something into it.

But maybe you refer to the following behavior of Maple that I overlooked: When hiding an equation label by Format>Equation Labels>Selection each instance of an equation label in a Maple input is replaced by the output the equation label is referring to. This could cause two unwanted effects: Firstly, all Maple inputs referring to equation labels to be hidden would blow up by output insertion. Secondly, this replacement process might be not reversible (although it is in the attached example on “hidden labels” in text passages; see Note 1).

With that in mind only two supposedly low hanging fruits are left from my original list:

• In a text passage or Maple input: Double click on a label reference to open the insert label dialogue (crtl-L) in order to change the reference (instead of deleting the reference and inserting a new reference). A nice time saver because I frequently have to correct or modify input.
• For larger documents: A search function for equation labels in a document.

Would this be feasible without changing the equation label iimplementaion too much?

In case a rethink of equation labels is something you consider it might be an opportunity to rename them to “expression labels” since they refer to much more than equations.

Labeling_inside_text_passages.mw

Although, I have not observed any issues with the pdf export for my examples, I fully support that there is a strong need for a working and bug free export function.

Maple made strong progress in providing solutions for industry. These guys need in most cases proper and (even more important) error free documentation to document their work.

I also tried rtf export for further processing with word which resulted in unsatisfactory screen layout (I remember missing equation labels in Maple 2020).

If Maple 2021 export to Latex is so good as it seems why not converting this by a “smart” integrated converter to pdf.