James
Well I guess the good news from knowing what model numbers we are working with is that the Aliexpress headset should be wired something like the Baofeng UV-5R since it lists that as suitable for that model. So the detail at
https://pinoutguide.com/HeadsetsHeadphon...nout.shtml then becomes useful.
Looking now at the GME, it lists their HS009 and HS010 as compatible and neither of these have room for an internal mic amp, nor the power supply voltage feed to run one. That makes it that both use an electret mic insert BUT not all inserts produce the same output voltage level for a given audio/noise level. The one from Jaycar may produce a lower level regardless. Back in the old days, the radio specs also included the microphone sensitivity and usually the impedance etc.. Those days are gone and minimal specs are now made available.
One thing that comes to mind is the way an electret mic works... it is essentially a capacitor that has a DC potential applied via an internal resistor and the variations in potential difference through the application of sound waves causes the assembly to produce an 'AC' signal. What concerns me is that the capacitance of the 'mic lead' may be swamping the mic's inherent capacity thus loading it and reducing that AC voltage. Where a preamp is built into the mic proper then this issue simply doesn't exist.
You mention becoming 'detached' from the cycle so can I suggest that you buy a few in-line-style 3.5 and 2.5mm stereo plugs
and sockets from Jaycar (etc) to create a couple of low-tensile short extension leads. If you come adrift, they are the weakest link and meant to break away. You can always re-manufacture these leads in that event. Simply use a thin stranded insulated wire from socket pin to plug pin for each connection.. And always care a spare cable !
In the short term you can use one of these plug-socket leads as an experimental test-bed to try alternate interconnections to get it going, measure any audio or control voltages.
Doug