I don't really think that first order speakers really need extra room treatment compared to most other designs. Still the Thiel SCS's somewhat unique concentric driver design eliminates the driver integration issues that are needed for optimal listening of most first order speakers.
A past long time contributor who stopped contributing when he became part of the commercial side of all this; Karl Shuemann of AudioMachina's first offering, though perhaps challenging to find, was a 2-way first order speaker which incorporated some wave guide principles. He seems to have abandoned the wave guide with his latter more ambitious and expensive designs. Though I've never heard any of them, they sure do look promising.
Though I doubt these are what you had in mind, as they meet your criterion and are purposely built to negate room interaction, I'll mention them: the Innersound speakers.
A past long time contributor who stopped contributing when he became part of the commercial side of all this; Karl Shuemann of AudioMachina's first offering, though perhaps challenging to find, was a 2-way first order speaker which incorporated some wave guide principles. He seems to have abandoned the wave guide with his latter more ambitious and expensive designs. Though I've never heard any of them, they sure do look promising.
Though I doubt these are what you had in mind, as they meet your criterion and are purposely built to negate room interaction, I'll mention them: the Innersound speakers.