Advice on fixing Vitodens 100-W

[ChristiaanV]

I've recently had some home renovations done, and we had underfloor heating installed instead of the radiators we had before. The heating system was connected to my 4 year old Viessmann Vitodens 100-W B1HC (35kW) and is controlled by a Honeywell T4M modulating thermostat using Opentherm.
Since then, it's been behaving strangely. It will constantly go into these short cycles when there's a call for heat, where the boiler fires up to 40 degrees, does a small overshoot to about 45 degrees and then immediately switches off again. The water in the pipes on average doesn't go above 23 degrees and the room temperature remains stuck at max. 19 degrees. I'm guessing it has something to do with the fact that the thermostat doesn't ask for hot enough water, and the boiler having too much power and a modulation ratio that's too small.
The problem seems like the same as this one: https://forum.heatinghelp.com/discussio ... rt-cycling
One of the commenters on that topic said he fixed his problem by temporarily setting the setpoint temperature to the maximum whenever there was a call for heat. I just bought the WiFi version of OTG. Any advice on how I can script a solution that temporarily increases the CH setpoint? Can I use some kind of REST/HTTP endpoint to control the OTG, or what is the recommended way of scripting something like this? I'm a software engineer with a (college) background in electronics (although it's been some time I did any electronics projects) but I don't know the first thing about heating systems. Any help or advice is greatly appreciated.
Thanks in advance!