Looks like you've uncovered a limitation of Zumero's parser. The short answer is, don't use MSSQL-style square brackets to delimit fields when talking to Zumero cloud DBs, instead use standard-SQL-style double quotes.
So:
create virtual table foo using zumero ("Id", "FirstName", "LastName", "Address");
instead of:
create virtual table foo using zumero ([Id], [FirstName], [LastName], [Address]);
Using the first example, you can then insert via:
insert into foo (FirstName, LastName) values ('Fred', 'Flintstone');
or
insert into foo ("FirstName", "LastName") values ('Barney', 'Rubble');
or any combination thereof.