Lightroom Classic no longer opens HDR in Photoshop as Rec. 2020/PQ 16-bit; now forces 32-bit and disables certain blend modes

I’m trying to understand whether this is a bug, a regression, or an intentional workflow change.

Until recently, I distinctly remember being able to use Lightroom Classic’s HDR workflow and choose Edit In > Photoshop, with the file opening in Photoshop as a 16 Bits/Channel HDR file using an HDR Rec. 2020 / PQ-style workflow. This preserved HDR headroom while still allowing normal 16-bit Photoshop layer operations and creative blending modes such as Overlay, Soft Light, Linear Light, etc.

Now, when I send an HDR image from Lightroom Classic to Photoshop, it opens as a 32 Bits/Channel document. That does preserve HDR luminance information, but it disables many important layer blending modes and tools, which breaks a lot of normal compositing/retouching workflows.

The confusing part is that Lightroom Classic 15.0 release notes mention updated External Editing support for exporting images to Photoshop in “16-bit or 32-bit HDR formats,” with support for HDR sRGB, HDR Rec. 2020, and HDR Display P3. That sounds like the exact workflow I remember using: 16-bit HDR, not only 32-bit linear HDR.

My questions:

1. Is Lightroom Classic still supposed to support sending HDR images to Photoshop as 16-bit HDR “Rec. 2020 PQ (16bpc)” Smart Object files (with original RAW data and ACR/Lightroom edits accessible via Smart Object)?
2. If yes, where is that setting? I cannot find a way to prevent Lightroom from sending HDR edits to Photoshop as 32-bit “Linear Rec. 2020 (32bpc)”.
3. If no, was the 16-bit HDR Photoshop handoff removed or changed after Lightroom Classic 15.0?
4. Is there any way to retain HDR headroom in Photoshop while staying in 16 Bits/Channel so that the full set of layer blend modes remains available, without having to open old 16 Bit .PSBs as a template? It appears that it is possible to “Duplicate layer” from a 32-bit “Lightroom>Edit as Smart Object in Photoshop” 32bit-HDR ACR Smart Object RAW projects, to one of my older “Lightroom>Edit as Smart Object in Photoshop” 16bit-HDR ACR Smart Object RAW projects, restoring my ability to use creative blending modes, but it is quite the hassle and I don’t know why it’s no longer accessible directly from Lightroom’s external editor preferences.

The practical issue is that 32-bit mode in Photoshop removes blend modes like Overlay, Soft Light, Linear Light, etc. For HDR photo editing, this makes the Lightroom-to-Photoshop round trip much less useful than a 16-bit HDR Rec. 2020/PQ workflow.

Current setup:

Lightroom Classic version: 15.3.1 Release Camera Raw 18.3 Build [202605261338-e36f8566]
Photoshop version: 27.7.0
Operating system: MacOS 26.2 M4 Pro 14 CPU/20 GPU 48GB RAM
File type/source: .NEF file in a ACR wrapped Smart Object with HDR headroom mode turned on

Steps to reproduce:

1. Enable HDR editing for an image in Lightroom Classic.
2. Use Edit In > Adobe Photoshop.
3. In Photoshop, check Image > Mode.
4. The document opens as 32 Bits/Channel.
5. Many normal Photoshop blend modes are unavailable.

Additionally, all configurations of “External editor preferences” in Lightroom show that the HDR handling defaults to 32bit, and it is greyed-out so I can’t change it.

Expected behavior:

There should be a way (as there used to be), to open the HDR image in Photoshop as a 16 Bits/Channel HDR Rec. 2020/PQ document, preserving HDR headroom while keeping normal 16-bit Photoshop blend modes available.

Actual behavior:

The file opens as 32 Bits/Channel, which preserves HDR but disables important blend modes and tools.

Can anyone confirm whether 16-bit HDR Rec. 2020 PQ “Edit in> Photoshop/Smart Object from Lightroom Classic to Photoshop is still supported? If this was changed, is there an official explanation or recommended replacement workflow?