As I wrote in DMsG the low level code that I had to use I overwrite (even the original version of it) only uses indexes to reference the tabs. There is nothing else the way they've implemented it. In fact if you look at any code manipulating tabs (say char_wizard) you'd see they all do it via indexes. For 5E you can see that when the tabs are defined they are stored purely by index - not name. You can reference the code behind the tab by name - but not the tab itself. That is index based.
Currently in 5E that is mapped out per comment in my code as follows for the PC and NPC sheets...
If someone has messed with that core order by changing that order rather than modifying the code the tab points to - or adding a new tab at the end (new index higher than 7) - then for sure my stuff would be displaying what your seeing.Code:-- window.parentcontrol.window.tabs.getIndex()
-- charsheet
-- 0 - none
-- 1 - main
-- 2 - skills
-- 3 - abilities
-- 4 - inventory
-- 5 - notes
-- 6 - logs
-- 7 - actions
-- npc
-- 0 - none
-- 1 - main_creature
-- 2 - text
There is no Index to name map - that is something that does not currently exist in tab controls to my knowledge (could be wrong) - I'd have to write it myself. It would have to be a map of what the original numbers were verses the name of the class window code behind the tab (which is not actually the tab - just what it points too).
I'm going to have to think on this as there is limited code that deals with the tabs themselves but mine is one of them. I think the new char_wizard is another - though it is its own tabs in that case. I did not consider that the 5E default tabs would actually be changed by someone (inserting things in between things rather than adding them to end) based on how the low level code is set up to function (not mine - well it is now as I had to add more intelligence to it for my stuff to work).
Gist being - yeah - mess with the low level tab indexing for 5E and my extension is not going to display properly as the wrong tabs are going to be extended/contracted and have the char_polymorphism sub window added in.
Only solution I can think of is I'd have to literally somehow determine the window name to tab index and make a map that I could use (if one does not already exist that I'm unaware of). I'll think on it though. Test my theory - turn off the extension messing with tab ordering in 5E and let me know if my stuff then appears correctly.

