IMO - and it it an opinion because I don't think there are any conventions for this - the better solution would be to make it into a separate "auxiliary" plugin. I don't know how you intend to serve your plugin/s but if it is from some public TW where the user is to drag'n drop, you can take advantage of the new "drag-pill" features, i.e tag both the main plugin and the aux plugin with a common tag and then present the single tag for people to drag'n drop into their TW.
BTW, this approach
ought to be a convention for serving plugins IMO because it is much more elegant to present a pretty
pill than some
$:/plugins/ugly/link. ...but we shouldn't be forced to
tag tiddlers to include them in such draggable pills. (See
here for elaboration).
<:-)