Hello I would assume this has been considered in the past when the level update and Engine update was introduced and likely in the aftermaths of people reaching those higher levels so could even be in the works but regardless this is me putting the suggestion on here.
With the introduction of ten more levels and with it +10 more daily design points the game was adapted by massively decreasing the research rate. lowering research rate with levels has always been an aspect of IGP but we went from 40% with level 20 to 10% with now level 30 and as such the proportion of point earned by the static design point per race has went up drastically. with now a 10 point research being strong whereas before 30+ was solid. This has greatly diminished the stratergies regarding development wars and the stratergies that came with it. Holding points was an interesting trade off of loss to potential gain and holding back on increasing the highest say Handling was important to gain an edge. With everyone on 1/4 of the research gains pushing Handling up by 30 ponits isnt traded off with substancial reason against which has took away a layer to IGP which is missed.
My proposal is an increase of car stats from 200 maximum to 300 maximum this has a precedent when we went up to 200 to compensate I think at the time for more tracks being introduced though was years back. This compensates for the +50% Design points we gained form our HQ and means the research power can be increased to compensate for the now 100 point gap thereby reintroducing a healthy development battle. I'd assume Research power would have to increase up to 30-60% which for a specific number would need testing for what suits what developers want cars to be around after say 15 and 20 races.
The points themselves in my opinion would benefit from maintaing the current CD to next season of +1, +2, and +3 but just stretching the current development curve of rather then expanding it. This would mean using the scenario of a 20 race season everyone currently goes into the following season with 40 ponits on average in their car stats but under the proposed system that 40 would still be the number we'd see but it would be the same as if we actually had 27 as the numbers get 1/3 taken away. Considering how curve of IGP stats this leads to early game choices being more impactful as aspects such as one point in Fuel Eco counts for more at these lower amounts. Those who race leagues such as ILC which manipulate cars down to lower stat starts will be familiar. This starting earlier on the stat curve mixed with research powers relevance increasing just gives players just overall more impactfull options in the whole half of the IGP that is off track.