I think they are planning to do just like in their proposal with SDN token : offset quaterly fee for Astar/Shibuya/Shiden intégration on subscan (~17k$ / 3 months) with rewards from Astar&SDN dApp staking.
I suppose that remaining fee, if not enterly covered by dApp rewards, will be requested through founding proposal.
If this is indeed the plan, the only advantage I see here is that the selling pressur induce by the 17k$ per 3 months may be spread over the 3 months period instead of all in one go after payment of founding proposal. On the other side, they will need a T2 support i.e. 75M ASTR to cover most of the fee.