I think it's untenable for asylum to be granted for reasons such as persecution due to religion or sexual orientation - there are simply too many people living in shitty countries for that to be sufficient reason.
Possibly for political dissidents - but restricted to known, high-profile dissidents.
Specifically having helped British armed forces: it needs to be part of their contract and on a case-by-case basis.
With war refugees, I'm expecting a move towards Denmark's model: with short-term residence permits (1 to 2 years) that are regularly re-evaluated. Individuals to be repatriated when their home country becomes safe (relative to their region - not UK levels of safety).
The most important changes which I see as inevitable will be stronger border controls, treaties for returns to home countries, removal to 3rd countries for processing (to avoid the huge leakage into the grey economy), restrictions on family reunification and restrictions on appeals (single appeal in a short time frame, rather than stringing out multiple appeals for years).
I think you know the current legal routes to asylum, and you're not asking in good faith. For the avoidance of doubt, I am very strongly against introducing asylum 'safe routes' into the UK or reception centres to allow people to claim UK asylum from other countries.
The way Europe's generosity has been taken advantage of - and human rights agreements corrupted - has set the path we're on. There's no going back.