Mortar joint size question

[cutthroat]

Hi, like most newbies, i have been lurking here for some time soaking in as much knowledge as possible. I have been doing some AutoCAD design of an dome oven and have come up with a question that I can't seem to find an answer for. I'll try to be clear.

Using an Indespensible Tool or not it appears to be a consensus that the interior edge of dome bricks should touch each other.

If a person used perfectly cut custom bricks that would require no increases in gap sizes from the interior to the exterior of the dome an even mortar joint thickness could be utilized throughout the construction and no shims etc would be required. Technically if all went perfectly a very beautiful dome interior (and exterior) could be created.

My question is: Would this be a bad plan? The construction would take more time, a lot of cutting and more bricks, but would there be heat or construction issues that anyone can foresee?

Input would be appreciated.