This passing remark of mine is not intended to change or refute any comments by anyone re round churches. I'm simply adding to the idea you presented:
Now, during Henry Sinclairs' lifetime the church at Nidaros(Trondheim) could hardly be called a round church. The Nidaros church was then a full-size gothic cathedral, one of the largest in northern Europe, and it's still there today. Various historical sources confirm the fact that there wasn't any round church in Trondheim at the time.
In my study of temple, group, earth grids applied sacred geometry ...as well as observation... I find that the most complex temples: Chartres, Rosslyn as examples, have a center of spin which is a spiritual reference point. That is, the whole energetic system of complex geometry spins thus creating a series of concentric rings. Also, this spinning (etheric) geometric system "keys" or "strobes" on specific bearings or directions around the circle. Any number of these "nodes" ("Critical Rotational Positions") may be created during the spin on the wheel's circumference and on any of the internal rings. This sets up an established (but dynamic) pattern in the outer ring, such as an 8-pointed Wheel. This pattern then provides the temple with a specific overall attunement and function for as long as that pattern is "set" in the ring. Some temples are physically built to that pattern, not that other etheric patterns can not be used by it, but the physical "set" provides an established system of initialization or reference.
An 8, or 12 sided temple are basic wheel formations but something as complex as Chartres, et al, will not SHOW these directions however they are there. Chartres is properly oriented NE which puts it in a saltire or "X" orientation. This sets a specific function over the whole spin, a reference orientation, which (in the NE) establishes a system for downloading spiritual programs. These programs, via Chartres (or anyother properly crafted temple oriented NE) are then best processed (manifested) by other temples oriented East, in a different cross ("Greek" cross, a "+" shape in the NSEW orientation). These other temples must be linked via common harmonic systems (geometry, etc.) for this to work. In the case of Chartres there are many "Marian" cathedrals ("Notre Dame(s)") that are in that matrix. For those temples that are not in more extended systems ...sort of just sitting there doing their own thing... and are oriented East, these will also do their spinning about and will create an etheric alignment in the X (NE orientation) or 8-pointed Wheel to facilitate a more efficient (clear, focused, appropriate terms of reference) spiritual program download. If the priest-operators do not design the best formats, or initiate the spin in some manner of prayer or whatever, then the place and people pretty much trust to God and carry on without their "ship" or temple doing much but keeping out all the wind and most of the water.
In the case of Bornholm, for example, the earth grid matrices are established in common with those at Rennes le Chateau, and those with the geometry at Chartres, Rosslyn, Montserrat basilica, Stonehenge, and others. So all of these sites would link into the common circuitry. The 8-point formatted ring is an important common harmonic but there are others more central that include the 8-point as a sub-system. Also, zodiacal temples pick up the 12-point ring as another powerful common harmonic. Henry Lincoln did some brilliant work in discovering the common grids in the Bornholm and Rennes le Chateau points which he connects with Jerusalem. (I don't, I connect with Mt. Sinai.) However this begins to become too complicated for this short note.
I am only pointing up the idea that any temple designer starts with the Wheel and works from there in facilitating the temple's intended function and also adjusting to many other variables: site within the larger earth grid systems, point where the place sits relative to telluric power lines and nodes, etc. etc.
William Buehler (Colorado)