Transferring a Vanguard S&S ISA to Trading 212 S&S and Cash ISAs

So I've got a Vanguard S&S ISA that I've been put some money in as well as a Trading 212 S&S ISA and a Trading 212 Cash ISA. I've got roughtly £400 of the £20k allowance remaining for the tax year. I'm saving to purchase a property so the majority of my savings are in the cash ISA over the S&S ISA.

The funds I've invested in my Vanguard S&S ISA are:

- Emerging Markets Stock Index Fund - Accumulation

- FTSE Global All Cap Index Fund Accumulation

- S&P 500 UCITS ETF - Distributing (VUSA)

  1. I was wondering whether an in species transfer would transfer all the funds or would some of them be sold?

  2. From an admin point of view, I'm thinking I should sell the funds manually first within Vanguard and then create a transfer to Trading 212 application so that the realised gains values don't get messed up. I'm assuming if I do the transfer, the values used to determine the realised gains values won't also get transferred?

  3. Is there any advantages of not selling them manually within Vanguard and letting the transfer handle any selling automatically?

  4. Once the transfer has taken place, am I correct in saying I can transfer however much I want between the S&S ISA and cash ISA?