It's a breaking change indeed, but one which we didn't anticipate, as a typedlist is used in a readonly fashion (as it's not an element which is to be edited).
The main issue is that to fix it, we have to call AcceptChanges, which causes a 5-6% performance loss and allocates 2-3% more memory. The change was mainly the result of bringing down the allocations and the time taken to fetch rows.
That said, the datatable based typedlist/views are legacy anyway and people shouldn't be using them in new projects so it's not that much of a big deal if we add that 5-6% performance back, as overall the fetch is quite slow compared to the queryspec/linq using poco approach:
Handcoded materializer using DbDataReader : 119,12ms (3,39ms) Enum: 0,94ms (0,01ms)
LLBLGen Pro v5.5.0.0 (v5.5.2), Poco typed view with QuerySpec : 140,99ms (0,53ms) Enum: 1,68ms (0,20ms)
LLBLGen Pro v5.5.0.0 (v5.5.2), DataTable based TypedView : 201,24ms (5,08ms) Enum: 3,17ms (0,06ms)
Memory usage, per iteration
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Handcoded materializer using DbDataReader : 15.170 KB (15.534.768 bytes)
LLBLGen Pro v5.5.0.0 (v5.5.2), Poco typed view with QuerySpec : 31.826 KB (32.590.512 bytes)
LLBLGen Pro v5.5.0.0 (v5.5.2), DataTable based TypedView : 55.324 KB (56.652.416 bytes)
(31000 rows)
With calling AcceptChanges the datatable based typedview (using the same pipeline as typedlists) takes ~207ms and allocates 56.5MB memory
We'll fix it in the next hotfix build.