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If "the trackage for each layout is basically a simple single oval which with no turnouts. Then the Tracks simply meet over The Bridge with double track and continues to the next single oval. The whole array is simply one large circular track" as you say... It makes more sense than ever to take the simple route of using ONE command station and two separate booster districts, or even a single booster and several circuit breaker power districts. Use twisted pair feeder bus wiring and RC filter/snubbers along the way (every 30 ft or so) to minimize long run issues.
Please keep your not DCC related topic rants to a minimum.