I thought I should provide an update, but it seems more appropriate to post it as an answer rather than as an edit to the original question. My apologies if this is not the preferred practice.
The question "Have the purists all gone on holiday?" was deliberately provocative and ironic, but while it did note the long-standing debate about our site's proclivities, the core intention was to raise the profile of an under-appreciated question. The comments on my meta post were constructive, and an edit to the title of the [prescriptive-grammar] question resulted in a substantial surge in views/votes/comments. Those comments appear to have stimulated the asker and several of the answerers to further refine their posts, creating a virtuous cycle of repeated bumping and additional views/engagement.
I'm delighted to report that the [prescriptive-grammar] question eventually achieved a significant response. Here are some stats on that question, as of 27 Sept 2018:
- Total views: 366
- Votes on question: 23 total (19 up, 4 down, net +15) [previously +3/-1 = +2]
- Answers: 6 [previously 4]
- Votes on answers: 40 total (24 up, 16 down)
- Comments: 44 total
- Votes on comments: 45 total
That gives an overall total of 158 separate contributions (answers, comments, votes), not counting all the edits to both question and answers. My assessment: while it took a bit of nudging, the question eventually achieved a substantial response from the EL&U community.
I'd love to report that the prescriptive-grammar question has now been resolved, but unfortunately I don't think that's the case. As John Lawler notes in his comment, the question itself is confusing, and involves "incorrect presuppositions"; to make matters worse, the OP edited in new elements in an attempt to clarify the issue but which only complicated the issue further.
So I have a dilemma.
I think the core question - does the conjunction "as well as" require a gerund-participial in the subordinate clause - has not been resolved. Generalist grammar sources simplistically say "the second verb takes the -ing form", and this appears to be support in CGEL, but opposed by Fowler. But the original question brings in other elements that result in other examples which don't involve subordinate clauses being discussed.
In addition, there's the matter of usage and whether there might be regional variation. I'm interested in whether the MW example - which sounds wrong to my Australian ears - is standard American usage, and whether British English prefers the gerund-participial.
I would appreciate your thoughts on whether a new EL&U question, strictly focusing on the "core" question above (but linking to the previous question and referencing the relevant points in it), would be
(a) regarded as a duplicate of the previous question, and
(b) too broad if it also asked about variation in regional usage?