IIRC, the BRP supplied optional '
Comfort Seats' for the RT models from 2010 until 2019 provided a 2"/50mm further 'set-back' for the lumbar support bulge, effectively reducing the space available on the pillion seat by that much, but by doing so, allowing the rider to slide back a bit further on the seat and gain a bit of extra leg stretch space - space which helped many of us!
By then adding a/mkt Highway pegs, you'll get even more leg room.
However, none of this ^ '
Comfort Seat' info applies to the 2020+ RT models (the Highway pegs bit does, tho!

) all of the later RT's came with separate seats for the rider and the pillion from the factory, altho some of the upmarket A/mkt alternatives still provide seats for them on a single seat pan...
Maybe this won't help
@olegeezer, but for anyone looking for something to suit the older model RT's, I don't know if you can still purchase the BRP supplied '
Comfort Seats' for these models from dealers, but they might be available from one or more of the various parts houses? Just be warned tho, if you're looking to get one of those, many of the 'other' seat variants, OEM/Original fittings, A/mkt alternatives, and others, were
called '
Comfort Seats' despite not having that extra room, so you need to check that the seat you are looking at actually does have the smaller 'lumbar support' bulge that shows there's more space for the rider - it's very easy to get the caught out by these '
Comfort Seat' labels that don't always mean the same thing!
Just Sayin'