No mashout fly sparge question

I have been fly sparging without mashout for a while now. But a thought has crossed my mind. My sparge water leaves the HLT boiling and passes through my pump and such at 1 quart per minute. By the time I have my MLT full of sparge water it still seems to be significantly under the target 168 generally around 150ish depending on the mash size, mash temp, ect. If my mash is taking an hour, will it affect my attenuation? Is the 168 sparge temp goal necessary to stop the enzymes and whatnot from creating more fermentables? Is the mashout really necessary? And if so, what steps do you take with large grainbills where a mashout would require more water than you need to ensure you hit target sparge temps?
The obvious answer would be a temperature mash using a recirculation system. But is this the only answer?

If you are fly sparging and not doing a mashout, get your sparge water up to 180-190. By the time you are done sparging, your grainbed should be right around 168 to 170 easily. If you don't get that hot, you're essentially doing a 2 hour mash give or take, which will give you a drier beer, but it will still be beer.

(And before anyone freaks out about tannin extraction, I know of several local microbreweries that do it this way with no ill effect, and I have also done it myself)

I have nothing to add because of the IIPA's but I seem to get better effiency when I do a mashout.

Well I fly sparge with boiling water and am still under my target. My pump is to blame for my massive heat loss I suppose. I think I'll increase my sparge water in rate to offset the loss (I feel like less heat loss happens at a higher rate when the flow is decreased)

Is there a formula I can run to calculate what temp water I would need and at what rate to finish out at 168 per pound of grain?

I also have been leaving my strike water in the tun and slowly draining everything at the same rate. Would draining most of the strike water decrease the thermal mass enough to raise the grainbed temp to the target at 1qt per minute?

I can't settle for a drier beer =P I need perfection in my brews!
I'm happy with my efficiency. 65% with a 22lb 5gallon batch I just did and 75% on regular brews

If you can, start your pump recirculating your hot water 10 to 15 minutes before you start sparging. Just put the output hose back in the top of your hot water vessel (while running your burner/heat source). This will heat up the pump and hoses, making heat loss minimal.

As for your other question, I am not quite sure what you mean? Do you mean drain the tun completely after your mash is done, before adding sparge water? If you do that, you're basically batch sparging at that point.

Yea that was my question. and yea I was thinking that would be the case. I need a second pump >_< I do a recirc in my tun for the last 10 minutes of my mash. I suppose I'll do it 20 minutes before the end of the mash and recirc my sparge water the last 10 minutes of the mash

Edit: actually, I'll just use gravity to get the sparge water into the tun and use my pump to get it out/recirc