Got it. This is my current setup
RTE.default {
enableWordClean = 1
removeTrailingBR = 1
removeComments = 1
removeTags = center, font, o:p, sdfield, u
removeTagsAndContents = link, meta, script, style, title
hidePStyleItems = h5,h6,pre,address,div
// buttons
showButtons = chMode, formatblock, insertcharacter, removeformat, unorderedlist, orderedlist, outdent, indent, link, copy, cut, paste, showhelp, about,line, bold,pastetoggle, pastebehaviour, pasteastext
buttons.pastetoggle.setActiveOnRteOpen = 1
buttons.pastetoggle.hidden = 1
}
as well as setup.override.rteCleanPasteBehaviour=pasteStructure or plainText in user TSConfig