Outdoor Power Equipment and Small Engines - Shindaiwa T270 BOGGING DOWN

Under full throttle or when edging the motor boggs down or losses power. I have cleaned the carb and filters any suggestions. I have 4 of these and they all do it. They Also are used everyday.

You don't say how old they are but I can comment in general.
The 2 cycle fuel ratio for most of these is 50/1. Some folks will toss in a little extra oil "for good measure" but doing this can foul the plug, clog the rings and restrict the exhaust.

I would suspect, your having said you cleaned the carbs, that you may have a carbon buildup problem. If you remove the muffler, you may be able to see into the cylinder; check the walls for scoring, etc. which might contribute to compression loss. Also check the rings if possible and ensure the exhaust port is clear and not restricted in any way by carbon buildup. If there is carbon buildup, remove it with a wooden dowel or something similar; anything but a metal tool so you don't score the port.

First make sure the exhaust system is clear of carbon, check the exhaust ports, muffler and spark arrestor and clean if needed.

Check carburetor adjustment, T270's have a slide valve TK carburetor and the bore and metering jet can wear over time, this will cause the unit to lean out, adjusting the carburetor to run good with a worn slide or bore will make a bigger difference when the unit is inverted as the fuel flows out of the jet faster and causes the mixture to "richen" this is a characteristic of this type of carburetor. It is not as noticeable when there is minimal wear to the slide and or bore.

The carbs on these have no adjustment. I also have cleaned the muffler, piston and exhaust ports.

I have a similar problem with my T270. When the unit is first started, it runs fine for several hours. However, once it gets warm/hot, it will not run at full power. It seems to be starved for power as when I press the primer bulb once, it will immediately run up to full power for a second or two and then revert to its less-than-full-power state. I generally have to quit working and wait till the next day.
Dealer rebuilt the carb one month ago.

Sounds like an air leak into the crankcase.

And where/how would I most likely find an air leak into the crankcase?

Spray carb cleaner around the crankcase cover and any other places air can leak with the engine running and listen for a change in the way the engine is running. This needs to be done when the trimmer starts messing up. What happens is that everything is cool and fitting snug until the engine warms up, then the block warms up, and the crankcase cover and other parts start warming and expanding and a leak develops, causing a lean condition. Then you have to wait for all parts to cool again for it to seal back up. I'm not saying this is the problem without doubt, but it does sound like what's happening.