Allow me to clarify. The custom filament spool on the Solidoodle Press fits nicely inside the unit - this provides a clean design with a minimal footprint. It really looks great and the spool doesn't hang off the back, which would take up extra space on your desk. There is no chip which locks the spool to the printer. Users are able to print with third party filament, but since Solidoodle can't control the quality or suitability of such filaments, we're not able to vouch for them.
We were very careful to strike a balance between offering our customers the improved design and performance of our internally-mounted spool while also allowing them to use third party filaments by mounting them externally. As to the referenced clause in the warranty and SoliCare policy, the relevant language states:
The Solidoodle Limited 60 Day Warranty (and SoliCare) "does not cover any issues...attributable to...(ii) use of improper filaments or other third party products with the printer."
The exclusion is specific to issues attributable to such use. If you are using third party filament and a belt breaks or you experience some other issue that is unrelated to the filament, that issue is covered. But if you are experimenting with a new filament and it strips the drive gear or causes some other damage to the extruder head, that issue is attributable to your use of third party filament and so is not covered.
We are working on supporting a wide array of the new filaments that are being introduced, but currently recommend using only Solidoodle PLA and ABS with our printers.
All that being said, if you break your printer doing something we think is really awesome, we might just hook you up 