Gridlock problems are particular to two party systems. A modern constitution would also include voting methods that don't result in a two party system.
You could also reduce the risk by the constitution itself being exempt from sunsetting and enumerating crucial rights and services therein.
Anyway it's not something that's ever going to be implemented anywhere, so it doesn't really matter if it could work.
The fundamental problem with incentives is that they're asymmetric in nature: The incentivee has a lot more time (and direct motivation) to come up with a way to game the incentive than the incentivizer can spend when setting it.
The only real way to address that is to revise incentives on a frequent and regular basis — but who wants to do that? Certainly not legislatures.
If I were writing the constitution for a representative democracy today, I think it would include mandatory sunsets for all legislation.
Yes, this would lead to the legislature spending a lot of time just reauthorizing existing legislation, but I would argue that the majority of new legislation being passed in modern representative democracies would be better off as revamps of existing legislation anyway.
You could also reduce the risk by the constitution itself being exempt from sunsetting and enumerating crucial rights and services therein.
Anyway it's not something that's ever going to be implemented anywhere, so it doesn't really matter if it could work.