hello,
How can I get my MikroTik online using a static public IP (/30) from one ISP, while routing my client network's internet traffic via the default route to a second ISP?
If I understood correctly, you have two providers connected to two router interfaces.
If so, the router will have two public IP addresses: one fixed from the first ISP, and the second IP from the second ISP, through which the clients operate.
So, what is the question or problem? 
hi @aldek
If my default route does not point to the public IP gateway,
the public IP cannot be pinged from an external network;
how can I ensure that my public IP is not the default gateway, yet remains accessible via that public IP?
without gateway, packets from MT does not know how to reach destination
so, yes
you will have two 0.0.0.0/0 GW on two different table
since it is advanced config, multiple GW, you will need at least firewall/mangle to mark incoming packets/connections for static_ip_wan, then put these marked connection on separate routing table and send them out trough static_ip_wan gateway
hi @npeca75 ,
The problem is that my public IP speed is low, so it’s not feasible to set the LAN connection's default gateway to the public IP.
I’m wondering if it’s possible to have this public IP active on my MikroTik without adding a route.
again ...
you will have TWO (2) gateway
one for normal_users
one for static_ip_wan
you will stil use "normal" GW from main routing table for "normal" lan users
static_ip_wan need to have separate routing table, incomming connections/packets for static_ip_wan need to be marked with FW/MANGLE and then put these marked packets in separate routing table