When TBH first got their big push a number of years ago, they were promoted as cheap, used natural or foundationless comb, and the idea was too cut off the honey comb from the actual TBH combs. Not many planned for extracting extra supers.
And while I understand the desire to super, (easier to extract, etc.) why not consider something other than a traditional TBH with solid bars, and then playing around with multiple sized bars?
Natural comb or foundationless systems can be used in any type hive. And some of them use the same concepts as a traditional TBH, yet allow one to super also, without any problems.
*You can build your TBH using standard frame tops, providing the required space to allow the bees into any placed supers. The you can use a quilt or other covering on the bars (like a Warre hive) before you place the top.
*You can also build a trench or long box hive, allowing you to super just like a traditional hive and yet have foundationless comb
Honestly, if you want a TBH, foundationless comb, and will build it yourself, there are several options that would not require splitting comb, spacers, etc. Splitting comb with spacers is easy. Putting them back together is another story.
Here is a trench style... http://www.bjornapiaries.com/uniquebeekeeping.html
Here is a little on TBH's.... http://www.bjornapiaries.com/topbarbeekeeping.html