Apartment Boiler Upgrade Building Regulations Flue Length

15 year old boiler in my apartment has started giving problems. Had a survey done for a replacement condensing boiler and was told that it wouldn't be possible to fit at the existing location due to the length of the flue leading out to the balcony.

Measurements specified were max 5000mm flue run, with an extra 500mm cost per turn, and if I understood correctly the flue turning from vertical to horizontal directly above the boiler counts towards this. Condensate shouldn't be an issue as there is a drain line below the boiler already.

Layout for reference existing boiler location in red, and existing flue (8000mm) in blue:

From what I can tell there are 3 options:

1. Run flue to the left wall (my idea, green in diagram), the apartment happens to be the last in a row on this floor so this end wall is available. It is under 4500mm away, so even with the 500mm "turn" it could just about work. However the last section in yellow is an external riser, would probably have to avoid this area, and what are the chances the management company would even allow placing the flue on this wall?
2. Move boiler closer to wall, not a great solution IMO considering the extra work required. The plumber specifically suggested moving towards balcony which isn't really workable considering it would be in the middle of the room in the way of the window...
3. "Assessment Procedure for Existing Dwellings", get a non condensing boiler installed due to the complexity, would be a very disappointing option.

I was advised to contact management company and I am currently waiting for a response from them. In the meantime I would like to get some opinions since I am holding off repairing the existing boiler if there is any chance of it being replaced. Has anyone had a similar situation in their apartment?