Lower the hard upper limit of rows in a single sheet

I have a spreadsheet that will never hold more than 200 rows, and some columns are always automatically filled. I’ve been filling the entire column with statements like IF(ISBLANK(previous cell)=FALSE,true value, "") in order to keep it blank before the row is used, but going all the way to 1M is overkill (and sometimes crashes Libreoffice), is there a way to hard limit the number of rows in a document?

I realise I could just extend the column formula for 200 rows or so, but it would feel much neater to hard limit the rows if at all possible.

Select the rows that are not needed, right click on the row indicator (on the left) and click hide. This will make the extra rows inaccessable (until they are selected in the same way, and ‘show’ is pressed).

+1! You can do the same thing with unnecessary redundant columns