Finding property - Unrealistic?

What other ways are there to get a suitable plot of land?

The only thing that really helps is to keep scouring all the mentioned channels daily: online, newspapers, knocking on doors, telling everyone that you are looking for a plot of land, whether people want to hear it or not. And when something suitable comes up, you have to be able to act very quickly. Therefore, do all your homework in advance with building costs, renovation costs, etc. Being selective is okay, but only beforehand. If you need too long to think, you're out.

I now have a job where I work from home and only occasionally have to go to the office or clients. That gives flexibility/stability regarding location choice.

Then you can make the search radius three digits ;)

I don't like to say it, but you really have to invest time or take what’s left or accordingly more expensive properties (used or from developers) that cannot be sold quite as quickly.

What other ways are there to get a suitable plot of land?

Besides the recommendation to buy an existing property, there is another pragmatic solution. The hacker would say "brute force." Offer more than the others for your dream plot of land, then it is easy. You are basically paying for the personal effort not put into the search. Problems that can be solved with money can also be solved with money.

A broker does (in the proper sense) exactly what you don't want, dealing with the topic (your wish) and investing time. For that, he actually receives the commission (currently not necessarily due to the market situation).

If it is supposed to be new, then probably only a developer will come into question where you still have to make the choice of tiles, toilet, etc. and that preferably in 1-2 appointments. Attention, as far as brokers are involved, the commission and additional costs apply to the entire construction project ;)

In BW or in areas where 2k rent for a terraced house is the norm, the rest is also expensive and with 200k equity you are probably rather in the midfield of the applicants than the spearhead of liquidity...
Intuitively, that might be enough for a plot of land where the middle terraced house plus terrace fits or half (small) plot for a detached or end terraced house, then 3k/sqm living space, 50k incidental construction costs, 50k for outdoor facilities, there will probably quickly be 800k and more for 150 sqm without a basement and luxury on a small plot. Min 600k loan then roughly corresponds again to the 2k rate.

Younger property (without major renovations) would have the advantage of just nodding along without having to think much.

The only thing that actually helps is to scour all the mentioned channels daily: online, newspapers, knocking on doors, telling everyone that you are looking for a plot of land, whether people want to hear it or not.

Full agreement ...

And if something suitable comes up, you have to be able to act very quickly. Therefore, do all the homework in advance with construction costs, renovation costs, etc. Being picky is okay, but only beforehand. Anyone who has to think too long is out.

... strongly underlined.

Then you could make the search radius triple-digit

No, that only brings more frustration rather than a higher probability of success, just like a less precise search.