Inserts extra space after Custom Token when used with Token Filter

The cause may be one of these other involved modules, but as far as I can tell the culprit is Footnotes:

https://www.drupal.org/project/token_filter (8.x-1.1)

https://www.drupal.org/project/token_custom (8.x-1.0-alpha2)

https://www.drupal.org/project/token_custom_plus (8.x-1.0)

(I noticed it when using Custom Tokens Plus, but it seems to happen with just Custom Tokens and Token Filter.)

Consider a custom token [custom:test] with definition:

<span>TEST</span>

where that definition does NOT have a space after the SPAN close.

Use a text format with no editor and no other filters except Footnotes and Token Filter. No matter what the order of the filter, if you use the token as:

In brackets so can see extra space ([custom:test])

You get:

In brackets so can see extra space (TEST )

With an extra space before the closing bracket.

It does not seem to happen with all tokens (for example, using [node:nid] is fine).

Thanks for your work on this module, which is otherwise very useful.