yep, very aware of that and in fact i warned about that in a note when i added the 3 separate images at the same time i renewed the MS version link in the initial post. There's in fact 3,249 map segments [tiles] in the US lower 48 image which isn't a problem for late model outdoor units using only this map but as you say extracting the PIOs or even combining several smaller tiles into one, would overcome the problem of this: when you add a topo on top of those 3249 tiles plus the basemap it'd be real easy to bust the 4,000 limit. And there's the rub of course, this isn't an NT map it's in OF so maybe someone could do that .....

Crazy thing is that a tile limit doesn't apply to Automotive units, the very unit type where a 4000 limit or even 2015 limit is not usually a problem. Why Garmin chose to make a tile limit for outdoor devices and not for car devices is freaking' beyond me! So with most topos only now being available in image form, taking account of the tiles already from basemap and topo the MS version would have to be used to make a small regional 'shortcut' map keeping under the unit's total tile limit to potentially take advantage of the 'richer' combined POIs. So if it's 'all too hard' to do it any other way [extract POIs or combine map tiles], we need a guinea pig in the states to try it out ... you got an outdoor device Strephon??? [hint hint, nudge nudge].

What might now seem to be a really stupid way to have made this map simply wasn't true at the time in 1999. Devices and media cards had only tiny memory sizes so fitting the entire US lower 48 Roads & Rec. anywhere was a pipe dream back then. 128MB was considered huge and you weren't going to bust the 2025 tiles limit easily even with that 'huge' space all filled up anyway, assuming you could afford the king's ransom to pay for the proprietary Garmin media card.