23 years in the 'Aviation Industry' and close on 10 in a marine environment and I've never seen a damaged Ti-Alloy fastener. With an ultimate tensile strength in the region of 30,000 (cheap 'n nasty)-200,000psi (aerospace quality) I think you'll experience tool failure before the fastener gives out
Tap a T30 Torx bit in nice and gentle, the T30 comes up at approx 5.4mm. With a tapered 'easy out' as per the link above you'll have to drill the screw head to to a greater depth, even then you'd be better off with a parallell easy out as opposed to the tapered version as it has a far greater surface contact area.
Just go for it, you'll enjoy doing it yourself and you'll wonder what all the drama was about, make sure you purchase a new screw first