You need a thermal path to the outside more than a heat sink under the LED board.
So the shelf would be fine even with a hole in the middle, as long as it’s under the emitters and guiding the heat to the outer perimeter.
You actually got one of the nicer SRK’s out today, some of them are even worse believe it or not.
You can salvage it by adding a shelf. This is easy if you have a lathe (which I did not) and doable by hand if not (as I did). Some 1 5.8’s bar stock is only about 1-2MM too large, so you just have to sand down that and it should press right in, you can glue it in place with some thermal adhesive if needed. Thread the screws through the shelf and up to the reflector to press the mcpcb agienst the shelf and it actually works quite well.
I made 20 like this last year and they range from ~8k lumen xm-l2 based to 17k lumen xhp50 based lights. Although the xhp50’s are not recommended on the stock mcpcb unless you have a very optimal heat path and at least 8 of them to share the load.
All of this said, with the stock LED’s you are looking at around ~4000 lumens all said and done if you have an 8x model. Not bad but the Q8 will get you more out of the box with less investment.
I have a SRK I didn’t feel like modding. So I just boosted the current and added thermal paste and plan on seeing how long it lasts. So far it is not doing better then expected, ~2400 lumens and still ticking. It is nice to use for dirty tasks since I don’t care about it.
I have several low profile copper heatsinks (60mm square 5mm thick) someplace… I bet that would help get the heat off the LEDs.
Thanks everyone for giving me ideas… I have already put in that I wish to purchase the Q8, as well as that nice slim triple emitter single 18650 light… those should hold off temptation for a couple of months or so, in the meantime I can try to find a driver, and some LEDs for this chunk o poo.
I did this to mine
Yea its a bit easier now that i have a bench sander i would hate to have to do it all by hand. I have done a few copper heat sinks by hand in the past but i used a file to get more of at once. I have to shave a reflector down so the LED wires dont touch now. I am weighting up either to do it by hand so i do not take much of or use bench sander or rotary tool. If it isn’t a big job doing it with course sand paper is easiest.
If you do make a shelf make sure you finish it of with a fine grit sandpaper so its smooth.
I think its easier for lads in the USA to find stuff in the sizes you need i have not been able to source copper in the sizes that i need from normal hardware shops. I wanted to buy a few sizes of copper and make different heat sinks.
it is a shelf there for the LED board to sit on, but its only contacting around the edge. a solid copper or aluminum “slug” pressed on beneath it would help the heat dissipation quite a bit.
Of just ask kiba-ru if he already has or can make an appropriately-sized Cu slug to wedge in there nice’n’snug!
I like doing it I am enjoy metal work for some reason even thought its amateur stuff i am doing.
I have asked before but he didn’t want to make it since not all SRK’s are the same and thus a one size fits all slug may not work in all lights without some extra sanding needed to make it fit.
I cant make batch of them to have them in stock because I wont be sure that they will fit. If smb really need it he can take measures and contact me.
OP I feel you… After seeing a pic I wanted one, so I read tons of reviews here and thought I knew what a good SRK was supposed to look like.
Ordered 1 on Ali and it was bad.
Got a refund.
Asked all the vendors if theirs were good referring to the refund
All but 5 disappeared overnight and a couple vendors said they were good.
So I ordered them all (different vendors)
All were bad but by then I learned about how many vendors never see what they sell an mostly are not rich people.
So I settled them in such a way the shipping was covered and manufacturer and actual shipper could refund the vendors, three thanked me and one still asks me advice when he is about to add new lights so it is all good.
I bought 10 XML2 NW for $23 and life is busy so only used 4 of them with a RMM driver in a SRK, lot of thermal paste, nice tint and easy operation, like it.
The poor state of current SRKs was a prime factor in starting the Q8.
But I have wild plans with the rest. Only got 3 or 4 ledded for reviews here only showed those to be good (old reviews) and now happy for changing 4 LEDs is doable bit up to 13 is ludicrous 
Funny all this talk about modding SRK’s. I am actually in the process of making a “mega SRK” like the Mega M6 RMM made if I can get the spacer made. Planning on building 2 of them at this point.
1 with 12x 319A’s 5000k 80cri as a photo light. Another with all the leftover LED’s I have laying around in order to put them to use.
I might even have enough left over LED’s to build a 3rd one. Yeah, I have that much stuff left over as “spare parts” from last years modding bonanza.