When I rebuild stop to double length platform, platform radius be the same as platform length!
So? My main problem with two tile stops is that some blocks are only one tile long. Apart from that, my stops have usually been two tiles long long before that, with one tile for bus/tram stop and one tile for mail stop. (As long as they are next to each other, the mail stop can be used by passengers as well.)
In previous version, "combino" tram even was two platform length and pass on one length take pax and nothing goes wrong. Today - Tram ride, transfer pax, but spamming me messages "platform too short". This thing unable to play and use "combino trams".
Using combinos on single tile stops have never really worked. Passengers in cars beyond the first tile would not be able to depart on single tile stops, and hence would just keep riding forever. The new message "platform too short" (at least I've never seen it before) was likely introduced to bring attention to this.
Other trams (Duwag) are too expensive to use it for citycenter trams.
That's one of many problems pak64 has beyond 2000. By 2030, almost everything has fallen apart in terms of profitability in my experience. (I think ships and airplanes are untouched, as they have stopped evolving long before that.)