From Gregor's point of view, what might be some positive aspects of his metamorphosis into an insect ?

On the surface, there isn't much positive about turning into bug. Gregor is trapped in his job by his duty to his family, but he dreams of the day when he can finally pay off their debts and quit his job. His need for freedom from the restrictive demands of work is expressed in his metamorphosis, by means of which he escapes.  The trade-off  is that Gregor is trapped in his own room.