RTB House DCO creative rendering issues with custom templates?

hey everyone, following up on the DCO underperformance thread from last week. after digging deeper, i'm pretty sure we've narrowed it down to a very specific technical block around creative rendering for our RTB House campaigns.

we're currently leveraging custom creative rendering templates for RTB House DCO, pushing some fairly complex dynamic elements into the ad units. the issue we're seeing is that some elements just aren't loading or displaying correctly, which results in blank spots or often, just fallback images. it's not consistent across all creatives or segments, which makes it super tricky to debug.

i'm suspecting it's either an issue with their JS parser struggling with our custom template logic, especialy when data structures are a bit nested, or perhaps a latency problem in loading specific assets for certain user segments. it's causing a major headache for our dynamic creative optimization.

here's a snippet from what looks like an internal RTB House console log, or at least something similar we've observed:

RTB_DCO_RENDER_ERROR: Failed to parse dynamic content for slot 'product_image'.
Reason: SyntaxError: Unexpected token '<' in JSON at position 123
Creative ID: 123456789
Timestamp: 2024-07-26T10:30:00Z

anyone else faced similar creative rendering issues with complex custom templates on RTB House? are there any specific debugging steps or known pitfalls to watch out for, maybe related to JS execution environments or custom data feed parsing? would appreciate any insights!