Microsoft Identity - Seeking best practices/recommendations for roles, claims, and policies in ASP netcore web api

I am new to Microsoft Identity Platform and want to get an idea of best practices and guidelines on Roles, Claims, and Policies. I have watched the videos from Matthijs Hoekstra (MSFT Microsoft Identity Platform Team) and the 'ASP.NET Core Authorization with Barry Dorrans'.

Our OData Web Api has 150+ controllers and most controller actions are CRUD (GET, POST, PATCH, and DELETE). We currently have 20 client apps that access our system. Currently our custom AuthZ logic handles 500+ claims and maps claims to roles via below snippet.

                        foreach (var role in roles) {
                            identity.AddClaim(new Claim("http://schemas.microsoft.com/ws/2008/06/identity/claims/role", role));

Our controller actions look something like this...

[Authorize(Roles = "AccountGet")]
public async Task<IActionResult> Get() {}

[Authorize(Roles = "AccountPost")]
public async Task<IActionResult> Post([FromBody] Account account) {}

[Authorize(Roles = "AccountPatch")]
public async Task<IActionResult> Patch([FromRoute] int id, [FromBody] Delta<Account> account){}

How should we setup Roles/Claims/Policies using Microsoft Identity Platform in such a way that the current authorization capability still works?