Yes, I’d advise against this. The store and forward system doesn’t use a flat file, but instead stores the binary objects to an internal database. As a small aside, this also means that “1 record” isn’t necessarily 1 value… it could be thousands of values (all of tags in a particular historical scan class, for example).
Experience has shown that there certainly is a point where the time it takes to store and retrieve the items from the local cache becomes greater than the time it takes to write them to the database, which is a bad situation. This can be helped by increasing the “forward size” to the final db from the default 25 to something bigger, like 250, but ultimately you will eventually still hit a wall.
One of our top goals for 7.8 is going to be to improve this system. In the mean time, I wouldn’t recommend setting it greater than 50k or so.