This shows an amazing multiple match on Cr1 location between 5 of my set of 12 relatives - TP, Je, SW, RM and RF. The other 7 - Ju, JG, E, A, B, MD and J do not appear. I used Qmatch with 3cM and P=3 and found 1963 segment-matches - 9 of which appear in the above screenshot with the central 7 marked in yellow comprising the amazing multiple just referred to.

Hoping that the Cr1 location 752721 was not a major genetic signpost which might rule it out as a marker specific to my set of relatives, I ran a check on GEDmatch using Segment Search at default settings (eg 7cM) for the 12 but noted a large number of segments matching each relative and commencing on location 752721 Cr1 as follows:

TF4905650	Ju	62
NB5414371	JG	1
EX2753498	SW	5
AM6017925	E	5
FM7651340	A	1
T456608	RF	56
M015511	RM	9
EK4706129	B	24
A341472	Je	1
PK9579087	MD	2
A789340	TP	0
GU4260044	J	116

None of the matches for each relative include any of the other 11 relatives, nor did any of the people in each list appear in any other list! A lefthand core of the 7 yellow 3cM segments above obviously forms the lefthand part of the 282 larger 7cM segments covered in the table. Each of Ju, RF, B and J show a distinct addition with each making 3rd party matches very readily, but the other 8 show less common distinct additions especially TP whose addition finds no matches at all. Nevertheless, as it seems obvious that the site (or rather its very common lefthand sub-3cM core) could be archaic, we continue with our rejection of it as relevant to deciding family relationships in our timeframe. We do this even though GEDmatch, in response to my approach to it on this, advised that location 752721 on Cr1 had no known genetic significance.