Hi kong, good question.
The 750 & 550 stacks are 'beefed up' (slightly thicker body 750, sealing ring 550). The filter its self is extremely light. From my trial fittings on my 550, it is quite firm. The back plate and stacks work together to provide this firm support. On the 550 there will be no need for additional support, of that I am certain. The 750, because of the additional stack length might benefit; but again I very much doubt it will be an issue. However, there are already air box mounts on the 750 that could be used if needed. One of the design goals was to keep things simple and clean, and avoid the need for extra little bits.
On an other note regarding oiling and cleaning. According to ITG, unless you are regularly riding on dusty roads, you should only have to clean / oil it once per season. During the season, a simple light wipe over the outside surface will remove light surface accumulation. So oiling / cleaning for most will be an end of season storage prep. deal. Milage is not a factor, the environment it is exposed to is.