Should I split my SQL Server table?

I have a table where the majority of columns are very, very often read (SELECTed) and are almost never updated.

I now need to add a set of columns to the same table (they are properties of the same entity), only these will be less often read, and also very often updated

If I add the new columns into the same table, will the UPDATEs interfere with the SELECTs?

Should I instead create a new table with a 1-to-1 relationship to the previous table?

If it matters I am using Azure SQL Server.