One thing I would like to see is a different trade weight applied to players depending on their contract setup.
For example:
If a player is near to the age of starting to think about retirement, and has 1 year left, their trade value should diminish considerably.
So a 29-30 year old (corner let's say) who has 1 year left on a contract, even if he is a great player and rated 90 plus, shouldn't command a trade weight that would necessitate a 1st round compensation. The reasoning being obvious, if a player already has a 10% chance of retirement it's very difficult to pull the trigger on giving them an extension which adds a ton of guaranteed money that could end up in a crippling dead cap hit on the chance they do in fact retire. So in essence they should be treated like one year rental pieces for the acquisition team.
However, a player in a similar spot: 29-30 years old with a 10% retirement chance, 90 plus rating, with a 4-5 year contract should be considered a legit 1st round trade weight. The team acquiring them will have their contract for the next 4-5 years but no risk of a nasty dead cap hit should the player retire.
Taking the contract length into account for players when traded will help teams on both ends imo. It makes it easier to get rid of older players if the asking price isn't outrageous for teams who want to rebuild through the draft, and it adds a layer of complexity because you will have legit options of short term rental pieces without giving up 1st rounders, so those years when you want to make a run at a title you can do it without ruining your draft capital.
Just something I had been thinking about.