I don't want to step on other toes, but it is rare, no mater what cleaner or techniques is used, that a new Bosch MAF will take a cleaning without killing it.
As for you ideas around 2 different set ups, don't waste your time trying. Our 50 year old engine can't put out much more power and with the current ECU's, they won't let you try and second guess them.
If you want to do anything, since you sure don't need any more horse power off road, work on improving what you have.
Sorry I haven't been on this forum for several years and missed "Disco Mikes" reply above.
I would of replied if I followed this old thread years ago.
For one thing I have had 95% success spray cleaning LR Mass Flow Meters, only failures were Mass Meters that had mechanical damage (screwdriver or stiff wire poking damage) to the sensors themselves. A couple short blasts only with cleaner then leave it alone.
Rover's "50 year old engines", there is a vast amount of engine power and torque gains to be found with any 3.9, 4.0 or 4.6 LR engine while maintaining stock valve diameters, cam specs and compression.
These above ugly ports, it gets worse the port misalignment to intake manifold ports.
Plastic toys from China have better QC than Land Rover's production engines.
A lot of performance gains can be had called using basic common sense engine building.
LR "trained mechanics" apply what they were trained to do and not think which is rather basic caveman engine repair or building. Throw parts at it until it runs and charge the customer for unneeded parts and labor time.
Another example LR used 1980's obsolete single squirt Lucas injector design.
Come on up to year 2000 at least with 4 hole 15 degree spray angle injectors.
ECU's what a joke they lean the **** out of these US engines to the tune of overheating, cracking blocks when a aftermarket (Mark Adams) chip properly fuels and still passes Calif. smog with ease.
"sure don't need any more horsepower off road", What a statement that was.
LR horsepower to weight ratio is already too low especially the lack of low rpm torque (3,100) these engines produce.
Torque moves these 4,600 plus pound LR tanks, how fast or lack of fast is controlled by horsepower.
"i'm a retired service manager of 30 years", you must have a very low mechanical ability before, during and after retiring from LR after reading these forum replies.
Did LR brainwash you to go by "the book" with their repair time charts cutting loss vs profit?
At my area I was lucky finding a LR service manager as well two of their real mechanics not just "techs" but real mechanics that understand, build and race LR engines on weekends as my personal friends, we spoke engine. Working with them while under the last two years of 7/100K mile extended warranty coverage.
Fast forward I now read LR members installing 5.7 sbc engines into LR's. Much cheaper also more hp, tq and reliability.
The trick is building a flexible, more horsepower and torque engine that operates at a real practical rpm with factory or almost near factory cam specs, compression and parts.
Anyone can build a hot rod engine with a big cam then there are those that understand engines and improve from their factory flaws. LR sure had, has their share of engine flaws judging by the aftermarket engine rebuilders like RPI, Rimmer Brothers as example.
LR engine the SBC engine of Europe.
The 215 Buick / Olds engine aluminum LR engine still has a large following group, myself included.