The repeater can do HBR3 link rate (8.1 Gbps per lane)

1080p only requires RBR link rate (1.62 Gbps per lane).

It is extremely unlikely that the capability would be reduced by that amount. It would be nice if they specified what the reduction is between repeaters. I would guess something like zero to three percent, unless something weird happens and the link rate is reduced from HBR3 to HBR2 (33% reduction) or more.

Distance depends on the cables you use. The following says 10m max in-between repeaters.

https://www.club-3d.com/en/reviews/13/cac_1007_displayport_1.4_active_repeater_4k120hz_hbr3_f-f/

So that would mean 40m total for cascade of 3? }–|–|–|–{