Den's are a tax on in the system, all they are designed to do is increase TVL - they add no value and personally, I'd get rid of them.
I'd feel more comfortable putting my money into a smart contract that doesn't leave my wallet rather than a scheme where you deposit funds and get magic money, source: unknown.
The fixed pool where the rewards are paid in inflation... with seemingly nothing backing up the value of the token? Maybe deposited user funds?
RE: Staking my $PIZZA Tokens on Vft Lab