and the Vf is high, so they are suitable for paralleling.
...i'm sure you realise that high Vf does not mean "suitability" for paralleling
...though i appreciate that paralleling high Vf LEDs is "especially" a good way to make the manufacture of the required switch-mode lamp driver cheaper and simpler.
-since high Vf LED strings can get rather high in voltage, and this voltage can be brought down by paralleling...(remember that cheap boost converters cant boost to very high voltages, due to topology limitations)
In other words, i know what you mean, but you have abbreviated your intended meaning a little too much, and it comes out a little ambiguous.
Modern LEDs are made in batches where the Vf is reasonably reliable
..i am also sure that you appreciate that there is no way of knowing whether or not your PCB assembly house have bothered to use LEDs from a single batch or not.
I would say that Western/European PCB assembly houses will say they have done this, but will not bother, -their margins are tight, due to Chinese competition, and they will simply use whichever reel of "same part number" LEDs they can source cheapest.....they may well not be from the same batch.
...another point is that all the Vf matching in the world is useless if you do not ensure tight thermal coupling between the paralleled LEDs aswell.
Tight thermal coupling is a job thats done by your lowly payed assembly staff....its them that will be trusted to thermal-glue your LED PCBs to the heatsink, and its them that you have to trust to evenly spread the thermal-glue behind the mounted LEDs, so as to give close thermal coupling of the LEDs.........and once they are glued down, there is no way for your quality staff to check the evennness of the thermal gluing, so you really are laying your trust (and your future) at the hands of your lowly payed assembly staff.
-The only way to check the evenness of thermal gluing is to rip the product to pieces and inspect it, -even then , the glue will have dried and you can't be sure about it.
You could do production tests involving running the LEDs and then measuring the current in all of the paralleled strings over a long period of time....but thats expensive.
So, to summarise, paralleling LEDs (with no series resistors to equalise the parallel currents) is an absolute last resort.
You would be best off avoiding paralleled LEDs like the plague.