Unusual piping cause short cycling?

D107

I discovered that what I thought was a 151ft 1" main zone monoflo system had two improvised additions.

First, when the third rad on the line was changed way back from standard convector to powered convector, to correct flow problems the return leg from that rad was connected not back to the 1" supply but to a dedicated 3/4" return that goes directly back to tee into the main return at the boiler about 15ft away.

Second, when the living room convector--which would have been the last in the line--was changed to power convector, a 3/4" direct branch supply line was teed off the main supply at boiler and run to the rad. The return leg of the rad then was piped into the main 1" line, now returning to the boiler at the end of its run.

Ever helpful Brad White had suggested a need for balancing valves (to prevent short-cycling I think) since a bit of very warm return water from the two rads would be returning sooner than the rest of the water.

My question is if let's say a buderus G-115 or 24x (no mod cons here) with logamatic is installed with outdoor reset and indoor sensor and the indoor sensor is put in a room and not on the return, wouldn't the short-cycling be avoided since whatever the temp of the return water, boiler would still have to reach the designated room temp at sensor location? Or does the Logamatic always have a sensor on the return anyway, by which it determines the outdoor reset, in which case this premature return could throw that all off? Does primary secondary solve this possibly by returning the early return water into primary loop?

I should add that with the current 25 yr old hydrotherm and beckett burner, no one has ever noticed a heat distribution problem.

I was hoping to keep this simple; makes me want to go back to one-pipe steam.

Thanks,

David