The photo's show the deck layout and the mast head. The blue line is the Dyneema 4 mm topping lift halyard. The blocks are small blocks with ball bearings.
Something like this
https://www.harken.com/en/shop/micro/22-mm-block/I was assuming you have a jib boom., but looking at photo's from the newer BRe's i see some with a mainsail boom lift. My boat is one of the earlier BRE's (nr. 7).
But for the main sail boom it would be similar, with the line going to the aft end of the boom. It needs to be slackened when sailing, so it won't obstruct the mainsail shape.
This is the simple version, may you have something more sophisticated in mind. May be the Forum readers with a recent BRe can post some photo's.
BR
Peter