Lease Extensions (player to player)

[Bodazafa]

Hey guys,

Currently, I lease planes for 1 year before using them myself.
Sometimes, players want to extend the lease but if I allow them to extend then they can choose any length they want (from what I understand) - which I do not want. lol

1/ Can we have an option to allow extensions (in the above case) where the owner of the plane can put in a fixed minimum AND maximum timeframe and then the lessee can choose an option from within that margin? 

2/ Another option could be to extend the current lease to be the same as the original lease - so 1 yr gets a 1yr extension option (owner controlled), 2 yr gets a 2 year option and so forth. 

I would like to have more control over the process without having to rely on the other guys word or what not.

Cheers.