Would it cause problems to receive full tables from our ISP but just filter it all out?

We're getting transit from a few providers and eventually we will get full tables from both. Today, however, our router would not be able to support full tables.

Instead of opening change orders after we replace the router, I was going to have both send full tables, but then filter everything out so it won't hit the RIB or FIB. This will also allow us to demo some routers and immediately receive full tables during the evaluation without having to reach out to the ISP to constantly update their export policies towards us.

Would this cause any performance issues on the underpowered router or are there any caveats I should know about?