Peckoltia, yes, it will not happen for a very long while for eels for the most part of what I seen in home aquariums, they not grow as fast as if out in the wild and I'm sure I not need to go over why that is.
For eels at a time will seemly grow faster where as at many times will grow slower and even sometime before every reaching their maximum size will grow then at the slowest pace for like for a sample here, both of my dragon eels had grown 4" in four years for as I not gotten to view their full bodies in the last two years for perhaps you readied that thread that both of these dragons moved across the front of the tank behind one another.
So yes, they growth quickness will not be so much of an issue that you have a good deal of time here and still however being that your eel is 2', it will in a year time period, seemly to grown much as for other times will appear to grown little or nothing at all.
It is the same thing for one other will be taking back a tess moray for I told him there as well that the eel be OK for a good while in the largest tank he had that he had time to setup a larger system to keep the eel. But he has seen that the cost would been so high and didn't wish to risk it.
So know that eels takes years to grow and I strongly believe that their growth is tampered by being cage in a tank what if large enough or not and still I stand by my knowing that it can still grow to its normal maximum size even if it be 15 years later for you will have that eel for a great many years, decades.
And while to just mix and match haphazardly is foolish and sometimes cruel, if one does his homework and uses discretion then a calculated risk can pay off far more than can be imagined. (another member said this once and I agree )
That is sad and very true TT, but one can only make his opinions known to those and it is left too that person to what they will want too do in if they would take you up on your advise or do it much the hard way.
And Peckoltia, my comment has nothing directly to do with you personal
I just hope that it works in the way you think it will that there be no problems.