Just a shout out and thank you to the devs

I just did a Python 3.6.4 build using all 4 cores, and it handled beautifully.  You can see where it switches from a single core for the ./configure into all for cores for the make -j4 altinstall

Time        CPU    load %cpu %sys %usr %nice %io %irq   CPU  C.St.
21:41:30: 1200MHz  1.00  26%   8%  17%   0%   0%   0% 57.2°C  0/8
21:41:35: 1200MHz  1.24  27%   9%  17%   0%   0%   0% 56.4°C  0/8
21:41:40: 1200MHz  1.22  26%   8%  17%   0%   0%   0% 57.1°C  0/8
21:41:45: 1200MHz  1.21  26%   8%  17%   0%   0%   0% 57.2°C  0/8
21:41:50: 1200MHz  1.27  26%   8%  18%   0%   0%   0% 57.4°C  0/8
21:41:55: 1200MHz  1.25  26%   9%  17%   0%   0%   0% 57.6°C  0/8
21:42:00: 1200MHz  1.23  26%   8%  18%   0%   0%   0% 58.0°C  0/8
21:42:06: 1200MHz  1.21  27%   9%  17%   0%   0%   0% 57.1°C  0/8
21:42:11: 1200MHz  1.27  26%   7%  18%   0%   0%   0% 58.1°C  0/8
21:42:16: 1200MHz  1.25  26%   7%  18%   0%   0%   0% 57.7°C  0/8
21:42:21: 1200MHz  1.23  27%  11%  15%   0%   0%   0% 58.2°C  0/8
21:42:30: 1200MHz  1.45  98%   7%  91%   0%   0%   0% 66.2°C  1/8
21:42:40: 1008MHz  1.92 100%   3%  96%   0%   0%   0% 66.2°C  2/8
21:42:51: 1008MHz  2.53 100%   2%  97%   0%   0%   0% 67.2°C  2/8
21:43:00: 1008MHz  2.65 100%   2%  97%   0%   0%   0% 68.6°C  2/8
Time        CPU    load %cpu %sys %usr %nice %io %irq   CPU  C.St.
21:43:12: 1008MHz  2.93 100%   3%  96%   0%   0%   0% 69.0°C  2/8
21:43:23: 1008MHz  3.31 100%   2%  97%   0%   0%   0% 70.7°C  3/8
21:43:33:  960MHz  3.49  99%   3%  96%   0%   0%   0% 70.3°C  3/8
21:43:44: 1008MHz  3.64  99%   4%  95%   0%   0%   0% 70.3°C  2/8
21:43:54:  960MHz  3.77 100%   2%  97%   0%   0%   0% 67.0°C  3/8
21:44:05:  960MHz  3.88 100%   3%  96%   0%   0%   0% 68.4°C  2/8
21:44:17: 1008MHz  4.05 100%   3%  96%   0%   0%   0% 72.0°C  3/8
21:44:25:  960MHz  4.04 100%   3%  96%   0%   0%   0% 68.6°C  2/8
21:44:34:  960MHz  4.11  99%   2%  97%   0%   0%   0% 71.8°C  3/8
21:44:45:  960MHz  4.23 100%   3%  95%   0%   0%   0% 71.3°C  3/8
21:44:54:  960MHz  4.22  99%   4%  95%   0%   0%   0% 72.8°C  2/8
21:45:03:  960MHz  4.26 100%   3%  95%   0%   0%   0% 70.3°C  3/8
21:45:12:  960MHz  4.29 100%   4%  95%   0%   0%   0% 69.0°C  2/8
21:45:20:  960MHz  4.27 100%   4%  94%   0%   0%   0% 69.6°C  3/8
21:45:29:  960MHz  4.30  99%   3%  95%   0%   0%   0% 73.1°C  3/8

I am very happy with the performance.  It didn't overheat (though I do have a passive heatsink, and no fan), and it was fully cranked from 21:42:30 to 21:49:55, and still 50% busy until 21:51:02, and basically went idle at 21:54:32, with a reported CPU temperature of 59.7°C.  It was 50.2°C by 21:58:43.

Linux opz2 4.14.18-sunxi #24 SMP Fri Feb 9 16:24:32 CET 2018 armv7l armv7l armv7l GNU/Linux

This is the 256M version that was prone to overheat with the legacy kernel.  No such problems with mainline.