Bryan Chapman Memorial 2019

[Ajax Bay]

Talgarth-Llangors-Bwlch-Llangynidr-Gilwern is another option to minimise distance on A roads

That is one clever option... basically you get rid of a climb at the cost of only 4 extra km... 

In what way would one "get rid of a climb"? The figures I offered above suggest 7m of climb saved.
Talgarth to Chainbridge
Routesheet 2017/2018: 41.2k + 325m on A379 and A40 and through Abergavenny
Probable routesheet 2019: 41.3k + 413m on A379 and A40, then right at Crickhowell to A4077 to Gilwern, then B4246/B4269 through Llanfoist to Llanellen, and south on A4042 through Llanover and left to Chainbridge
@Somnolent's option to minimise A roads: 44.5k + 433m going via Llangorse and Bwlch to Llangynidr, then B4558 and staying on A4077 through Gilwern, then B4246/B4269 through Llanfoist to Llanellen, and south on A4042 through Llanover and left to Chainbridge

[WATW has left the building]

When I look at the amended route, it seems like the climb is disappeared, replaced by some up and down and a lower gap through the Brecon Beacons mountains

That's what I meant