OSPF between two sites but not accept default route from ABR

I'm not sure if this is the right way to do this but I'm weighing up the best options to set this up. I have the option to use BGP and it might be the better option but tell me what you think.

I have a main firewall in Area 0 which is currently redistributing the default route to the inet, ospf, bgp, connected etc into the network as intended. We have some remote sites that are connected via some means, be it, ipsec tunnel, or mpls etc etc. Basically I'd like to do away with having to change statics on the remote sites and making it all dynamic.

The problem is each site has it's own default route to the internet which I need to keep but want to have the local remote site subnets announced back to the main firewall. because they all need to talk in a mesh config. If I create a new Area 1 on the main firewall and make it a stub and call the remote Area 1 stub, this works except the default route is overwritten with IA on the other side of the main firewall which I need to avoid.

Would using Stub no summary fix this? I'll try test this virtually next week either way but thought I'd see if I'm going the right way about this.

Thanks