Correct. The cone base is the major issue as the bottom is different to accept the Tri Clamp fitting. I almost bought a standard with the intention of upgrading to tri-clamps down the road and found that out. Unfortunately it's not as easy as just punching a bigger hole.
If you can find a good welder they can be upgraded.
I did 4 Blichmann's for a local brewery.
I converted them to be the same in construction as the Morebeer conicals.
The bottom port was increased to 1 1/2"
The racking port was increased to 1"
I also built racking arms with an indicator for each of them.
damn.. I was hoping.... i had done a little searching and had seen that some people had thought it was possible becuase they have smaller tri-clamp fittings and gave some links to brewers hardware and some other sources.
I have a Blichmann conical with standard fittings. I love it. Although I've never used the tri clamps, I find the standards are easy to use and clean. Just my opinion. At the time I couldn't see spending the extra $ to get tri-clamp fittings. Again, just my opinion. I'm completely satisfied.