"I wish ao3 would let me-"
It probably does, you just gotta learn how to do it.
"I wanna see fics for only my opt"
Go to either fandom tag or your ships tag, (if you're doing fandom tag you have to add your ship in the 'relationship' section),go to fliters (mobile) or the right hand side (desktop), go to the 'search within results' area and put in otp:true just like that click 'sort and filter' And it'll pull up all fics with just your otp.
(EDIT: if you wanna do this but still have other parings try otp:false instead of otp:true)
"I wanna sort by _____ not 'Date updated'"
Go to 'filters' or right, theirs a drop down and you can change it to 'author' 'title' 'date posted' ect their are more options. Pick one, click 'sort and filter'
"I don't wanna see /reader"
Filter or Right, go to 'search within results' type in -/reader like that, click 'sort and filter'. No more /reader
"I don't want explicit works"
You know where we're going Right or filter. 'Exclude' section. 'Ratings' click the box that says 'explicit'
Obviously if people don't tag shit correctly it's not gonna work but yeah you just gotta learn how the tagging works. For better tutorials go to TikTok and search 'ao3 tutorials' you can do just about everything.