Trying to understand routing & IPSEC

I know I’m getting closer to overall understanding - but I’m stuck on this part.

Remote location:
bLookback bridge, no ports, static address 10.255.255.2
bInternet bridge, all physical ports, LAN 192.168.1.12/24
dynamically receives 10.21.3.3 to bInternet bridge via IPSEC

known routes:

 0 ADS  dst-address=0.0.0.0/0 gateway=192.168.1.1 gateway-status=192.168.1.1 reach
able via  bInternet distance=1 scope=30 target-scope=10 vrf-interface=bInternet 
 1 ADC  dst-address=10.21.3.0/24 pref-src=10.21.3.3 gateway=bInternet gateway-stat
us=bInternet reachable distance=0 scope=10 
 2 ADC  dst-address=10.255.255.2/32 pref-src=10.255.255.2 gateway=bLoopback gatewa
y-status=bLoopback reachable distance=0 scope=10 
 3 ADC  dst-address=169.254.1.0/24 pref-src=169.254.1.3 gateway=bInternet gateway-
status=bInternet reachable distance=0 scope=10 
 4 A S  dst-address=192.168.0.0/24 gateway=10.21.3.1 gateway-status=10.21.3.1 reac
hable via  bInternet distance=1 scope=30 target-scope=10 
 5 ADC  dst-address=192.168.1.0/24 pref-src=192.168.1.30 gateway=bInternet gateway
-status=bInternet reachable distance=0 scope=10

route to HQ 192.168.0.0/24 statically configured. For now.

HQ has
bLookback bridge, no ports, static address 10.255.255.1
bLAN bridge, all physical ports 2-5, LAN 192.168.0.1/24
10.21.3.1/24 assigned to ether1 as IPSEC server

In the mode config for the remote site I have included the LAN 192.168.0.0/24, the IPSEC network 10.21.3.0/24, and the “loopback network” 10.255.255.0/24 in Split Include.

IPSEC connects and server & remote can communicate. From the remote, which is loopback address 10.255.255.2, I can ping both 10.255.255.1 (the HQ router) and 10.255.255.3 (a server inside the HQ LAN). However, I cannot reach 10.255.255.2 (the remote loopback IP) from either of the HQ locations. I can reach the remote IPSEC address of 10.21.3.3 as well as remote LAN hosts via NAT.

So my questions:

  1. Where does the remote have a route defined to able to reach 10.255.255.1 & 10.255.255.3? I don’t see it in the routing table shown above yet it works. I’m guessing it has something to do with my including it in the “Split Include” - as I do see a dynamic src-nat rule created that maps 10.255.255.0/24 to 10.21.3.3. Having just typed that I guess I already answered myself for this one…

  2. More importantly - if it works in that direction why doesn’t the reverse work? I’ve tried various src-nat rules on the HQ router with no effect.

  1. No routes are needed…
    Right after the postrouting, before the packet leaves the router, the IPsec policy, if there is any, is checked…
    https://wiki.mikrotik.com/wiki/Manual:Packet_Flow