I would expect this to volatilise, (and lose), low molecular weight flavour chemicals,
and,
start to degrade higher molecular weight flavour chemicals.
Bit late in the UK, but ambient airdrying should retain more flavour chemicals.
If you have the time and enough mint,
I would try some fresh mint, (as it is clearly too late to air dry in the UK now),
probably 'opened' up with herb scissors.
I would expect this to volatilise, (and lose), low molecular weight flavour chemicals,
and,
start to degrade higher molecular weight flavour chemicals.
Bit late in the UK, but ambient airdrying should retain more flavour chemicals.