I use only eBGP, on a closed network, and it is very easy to get going on MikroTik.
Only set an AS number from the private range, and set "redistribute connected", then add Peer
items for the directly connected routers with nexthop-choice=force-self ttl=1 and the peer AS and IP.
Optionally (recommended) add a simple output filter that accepts your network range and discards all others,
add action=accept chain=filter-out prefix=10.0.0.0/8 prefix-length=8-32
add action=discard chain=filter-out
From then on, no routing worries anymore