Yes tape on a frame is illegal but the only time it would matter is at nationals. This was the response sfrom the USAC tech director regarding wheel covers, tape on the frame to creat a foil would be in the same ball park.

We made an exception last year as it was the first year we were using UCI
bike rules for National Championships. This was done as the change had
caught most of our members off guard. Given that this is the second year we
have followed international rules for all National Championships, no such
exception is planned for this year. That means that wheel covers are not
allowed in any races. The UCI rules specify that nothing may be added to
equipment that serves no other purpose than to reduce wind resistance. That
is the case for wheel covers.

Tri spokes are allowed on the track and for road time trial events, but they
are not allowed for massed start road races. I hope that answers your
questions. Please let me know if you have any further questions.

Shawn Farrell
Technical Director