WORKDAY formula in Power BI

I have been looking for a Formular equal to Excels <=WORKDAY(start_date, days, [holidays])>, maybe that would be the Solution:

// FnWorkingDays 
/*
@Startdate type DATE
@NumOfDays  type INT // negative counts back
@HDays     type Table, 
*/

let FnWorkingDays = (StartDate as date, NumOfDays as number, optional Holidays as table) as date =>
   
let
  // get Holidays from Table
  ListOfHolidays = if Holidays = null then {} else Table.Column(Holidays,"ColumnNameFromHolydayTable"),
  // Convert Dates into Numbers for Quiker Search
  NumListOfHolidays = List.Transform(ListOfHolidays ,each Number.From(_)),
  // Define the Direction of Count, Negativ: Backwards
  AddDayDirection = if NumOfDays<0 then -1 else 1,
  // make NumOfDays Absolute for Count
  NumOfDaysAbs = Number.Abs(NumOfDays),
  // generate a Datelist with to many dates
  GenerateListDates = List.Dates( StartDate, NumOfDaysAbs*3, #duration(1*AddDayDirection,0,0,0)),
  // Select all none Weendend dates
  ListDatesNoWeekend = List.Select(GenerateListDates,(_)=>Date.DayOfWeek(_, Day.Monday) < 5),
  // Select all none Holydaydates
  ListDatesNoHoliday = List.Select(ListDatesNoWeekend,(_)=>List.PositionOf(NumListOfHolidays,Number.From(_))=-1),
  // Pick the NumOfDays + 1 from list
  ListDates = List.LastN(List.FirstN(ListDatesNoHoliday,NumOfDaysAbs+1),1),
  // Output last Date
  outputDate = ListDates{0}
in
  outputDate
in
  FnWorkingDays

My first attempt was to Build the Func. with List.Generate(), couldn´t to work Proberly.

I expect this Function has a Overhead Problem with to Many Records, therefor please comment 

The simplest way I found to calculate this without considering holidays (only weekends) is to use a SWITCH function on WEEKDAY of the date:

[Date] + SWITCH(WEEKDAY([Date]), 1, 3, 2, 3, 3, 3, 4, 5, 5, 5, 6, 5, 7, 4)

What this does is:

• Sun → Wed (+3)
• Mon → Thur (+3)
• Tue → Fri (+3)
• Wed → Next Mon (+5)
• Thur → Next Tue (+5)
• Fri → Next Wed (+5)
• Sat → Next Wed (+4)