Start and stop "frame" bits are important in asynchronous communication as they provide a way to sychronise the receiving bit clock with the stream being sent
if you send 128 bits of data the two clocks must agree in frequency to better than 0.4%. Most crystal oscillators are much better than 4000ppm
so it could work. but I've not seen such a scheme ever used.
Also the better the clock agreement the better the noise immunity of the system - towards the end of the packet the signal degades as the sampling point drifts towards the edge of the bits.
However most UARTSs send only 8 bits of data between each pair of frame bits. this requires only 5% speed accuracy making communication practical with a cheap ceramic resonator, or even a good RC oscillator.
If you want to communicate with a PC you will need to use a line discipline that it understands, that typically means no more than 8 data bits between the start and stop bits, so transmitting 128 bits of data will require a total of 160 bits on the wire.