I have an old dahon matrix. Around 10 years old.

I'm thinking about putting a bit of work into it, maybe see if I can make it an okay rider.

My idea so far is basically to take out the front and install a single 50t, keep the back (it's acera or something), install drop bars and STI shifters.

Replace the front very heavy fork too.

It's really heavy though!

Have there been any advancements in folding bike frame tech in the past 10 years? So that it would be better to just sell this old bike and start from scratch?

https://www.thorusa.com/images/dahon/...ded/matrix.jpg
a new one is 650 dlr .They are discontinued but a few ones are still available.. check out the pidc above and see if yours is different. I think the ealry ones were more or less the same frame as a Espresso...
post a picture and we can tell you more ....

Kind of like this:

https://dahonchile.wordpress.com/

only it has been neglected for several years, has rust in a few places.

Eh, right now I have my heart set on a montague, I wonder how much I could get for it on ebay.

I think it is worth it. The Espresso is pretty much the same thing. Here's the form mine eventually took.

Apparently MTB and Road front deraileurs do not play with STI's the same way --- you need a road der. if you want to do the front. Since the bike is heavy, you should keep it double. I had an MTB crank on hand... anyway, Shimano's CX70 FD will work with STI's and still do top pull, which is necessary for this bike. I have one but have not installed it yet. The top pull FD in the photo rubs too much. I used some free old Sora 3x8 shifters. A good saddle and a new seatpost helped the weight a lot.

Hi
Re front drylialer. They have tooth compatibility. So often a road version would fit a mbt and vese versa.
I dont agree about avoiding a tripple to save weight. If its a heavy bike you want the range more than saving a few grams.