Configuring Notepad++ for code folding - configuration

Question

I have a file which conforms to the following standard:
# comment
<section> # comment
{variant1,variant2,...}
a="bar"
b="b\\a\"r"
[array]
[+]
elem="foo"
[+]
elem="bar"
[/]
c=."42"
d=."xDebb1eD0e5Da11a5"
e=."%101010"
f=#"xaa bb cc dd"
{/}
</>
I have defined a new 'language' in Notepad++ and got all my syntax highlighting working well:
Comment Line Style -> Open: # (red)
Operator Style -> Operators 1: = (yellow)
Operator Style -> Delimiter 1 -> Open : < (yellow)
-> Close : >
Delimiter 2 -> Open : [+ (blue)
-> Close : ]
Delimiter 3 -> Open : { (orange)
-> Close : }
Delimiter 4 -> Open : " (cyan)
-> Escape: \
-> Close : "
Delimiter 5 -> Open : ." (lime)
-> Close : "
Delimiter 6 -> Open : #" (green)
-> Close : "
Delimiter 7 -> Open : [ (purple)
-> Close : ]
...But after much searching and reading I cannot work out how to get Notepad++/Scintilla to fold the the [array], {variant} and <section> chunks of the file (which runs to several thousand lines).
I notice that if I highlight a file as HTML, then any tag (html, body, foo, wibble, etc) all fold as expected - which I will need here as the <section>, {variant} and [array] names are arbitrary.
I have worked out that if a character is defined as a delimiter, the fold'er will refuse to fold on any string which starts-with that character.
My question: With regard to this file format, how do I get Notepad++ to fold according to these rules:
Rule 1 -> Starts with: <*>
Ends with: </>
Rule 2 -> Starts with: {*}
Ends with: {/}
Rule 3 -> Starts with: [*] but not [+]
Ends with: [/]