Here are some sources.
First In James Falkners Great and Glorious days dealing with Qudenarde on page146:
The french were coming on in dense battalion columns, - due to the close country it was difficult to find a place to form. The Prussians , although out-numbered, where already in line and had a distinct advantage in the initial exchanges of fire. A vicious close-range musketry battle blew upwith astonishing speed. Both sides were usung versions of the highly effective platoon fiering method to deliver continuous fire, but the prussians were rather more proficient at this technique.
Sadly he does not give any sources for this... I do think he makes other mentions of it, but finding it will take time.
When it comes to early adoption in the English/scotish armies from David Blackmore:
Relating to the war in Ireland in 1689
The Weather for two or three days proved pretty fair, and the soldiers were exercised with firing at Marks; but it was observable, that a great many of the new men who had match-locks, had little so little skill in placing of their maches true, that scare one of them in four could fire their Pieces off; and those that did, thought they had done a feat if the gun fired, never minding what they shot at.
Source: Douglass, Schola Martis f. 219r.
From the same source.
Then, on 29th September, Liutenant-General Douglass exerciced the regiments of the first line, teaching them how to fire by platoons.
The author add, "Whilst this provides clear evidence of the introduction of platoon fireing, there are, unfortunaliy, no details given on how it was conducted.
Also from the diary of General-Major Hugh Mackey in scotland at the same time.
In his Diary he described how, before the battle of Killiekrankie in 1689, he had "commanded the officer, commanding battalinos, to begin their firing at the distance of 100 paces by platoons, to discurage the approching highlanders meeting with continual fire"
Source: Obeservations relating to military exercise as now practisedin the English army, Lloyd's evening post and british chronical,(london 1759) 28-30 march 1759 p. 310 the piece was writen in 1757
The author feels this proves Platoon fire as in the Scotish army in 1689(he does point out that platoon fire was not effective in this instance.)
In 1693 a drill book was published in Edinburgh with a title page that stated it included "the rules of war in the day of battle, when encountering with the enemy"
Source. Anon. The complete milita-man (London 1760)
This was in part a reprint of the drill book of 1690, the first issued under William and Mary, but which was limited to the infanty drill and did not include the "rules of war" Source: Anon, A system of camp disiplin.... to which is added General Kane's Campaigns of King William (London 1757) p 59
Acording to the introduction to thr 1693 Edinburgh editino Sir Thomas Livingstone, who had succeeded MacKay to the command in Scotland, had revised and corrected the earlier edition, as well as adding the exercise of dragoons and also adding "Liutenant General MacKay's Rules of war for the infantry, to be observed when they are to encounter with the enemie in the day of battel.
Source: Same as above
[From the author]Given the offcial nature of this publication, and it's recomendation to the Scots and English armies, there would seem to be no reason to not accept MacKay's rules as representing the currenty practice in the dutch army that was adoptedby the English and Scots armies and that it was an aproved description of battlefield doctrine for all three allied armies from 1689 onwards.
[From the author] Included in Mackay's rules were detialed instruction on how platoon firing was to be Organised and conducted.
The book then shows the doctrine layed out by MacKay.