Ox burns 5 fuel, which is not good early when the rest of your ships burn 1, 2, maybe 3 fuel. Also, Ox profile is high, which is bad for stealth.
First year in the game is mostly small ships for me. Year two is when I may use a capital or two, but still early enough that I am still using what I can find and upgrading the fleet. I typically assemble the final fleet by year five or six. Colonies are still not very profitable until they reach size 6 at about year ten or later. For me at least, I avoid tugs for the first two years minimum. I get tugs later when I have Prometheus or two in the fleet to support long distance trips for a typical 200k bounty-sized fleet with many big ships.
Early game when I may want Apogee with burn 20, I suck up it and slap Augmented Engines on it. I usually do it only if I want to use starter Apogee instead of a Dram for a solo mission out in the fridge if I need to haul more than fuel.