The question will be why do you want to increase the REIT allocation from your traditional portfolio ?
The top 10 holdings of CSIF (CH) III Real Estate World ex CH -
Pension Fund ZB are already present in VT (even if their weight average between 0,10 to 0,06%)…
You can search them in the HOLDINGS section and there is 9,823 of them as of 01/31/2024.
Also traditional companies already own real estate within their investments allocations (e.g. Amazon owns storage, LVMH owns shops …).