hello. i didn't find this problem in the list, so I decided to create this topic.
the problem:
when we use incoming/outgoing arrows ( ->] / <-] ) the anchors are not layering with each other

@startuml
!pragma teoz true
{start1} Bob ->] : first something
{start2} Bob ->] : second something
{end1} Bob <-]: first return
{end2} Bob <-]: second return
{start1} <-> {end1}: \nfirst duration
{start2} <-> {end2}: \nsecond duration
@enduml

but when we replace incoming/outgoing arrows ( ->] / <-] ) to participant-to-participant line the anchors are layering with each other, what hinders the readability of the diagram.

@startuml
!pragma teoz true
{start1} Bob -> Alice : first something
{start2} Bob -> Alice : second something
{end1} Bob <- Alice: first return
{end2} Bob <- Alice: second return
{start1} <-> {end1}: \nfirst duration
{start2} <-> {end2}: \nsecond duration
@enduml

maybe there is some solution for layering participant-to-participant anchors layering problem, but i didn't find it. hoping for solution for this problem.