Renew Hardware of UP! Mini to least "state of the art" of this modell

Nearly 5 years after buying I activated my UP! Mini of the first generation some days ago.

From being excited after the first prints came disillusion because of the limitations of the printer (small buildroom, long printing time in comparison to actual modells, unevenly distributed hear over the full surface ot theheatbed, …).

Since the printer was long time not used I’m thinking about how the printer can be modded/upgraded to be as up to date as this printer can be (for a reasonable amount of money).

As far as I can say the most urgent problem is the heatbed.
My ABS prints have warping if I print too large (which doesn’t mean very big because of the limited build room) or near the edges of the heatbed.

I found an old thread in this forum, where the user changed the heatbed but independently of the mentioned price for the spare parts being one third of the whole price I paid for the printer, the spare part does not seem to be provided any longer.
Additionally for nearly the same price as of the spare heatbed part I get newer devices of some good brands in the mean time.

But right now I don’t feel to give up on this litle buddy.

So what’s your advice and what should be useful upgrades?