That audio cutting out in silent passages is pretty much the norm with those receivers/transmitters combo units. FiiO confirmed, IIRC, it, like it was on the earlier BTA30 (non-Pro) thread or something on Head-Fi.

Check these threads: https://www.head-fi.org/threads/fiio-bta30%EF%BC%8Chi-fi-desktop-bluetooth-receiver-transmitter%EF%BC%8Crca-optical-coaxial-interface.926876/page-39 and https://www.head-fi.org/threads/fiio-bta30pro-create-a-comprehensive-home-bluetooth-system-fiios-high-fidelity-bluetooth-transceiver-bta30-pro.960334/page-23

You basically have to play white noise or something, forgot now, to prevent the cutting out issue.

Look into the KB9P AptX Adaptive USB transmitter dongle, they're like $15-20 from AliExpress. It's not LDAC, but it's maybe the best Bluetooth transmitter available right now before those AptX Lossless dongles finally arrive.

This is the AptX Adaptive/AptX Lossless/etc. USB transmitter dongles (like KB9P, etc.) thread on Head-Fi, they talk about other Bluetooth stuff there too: https://www.head-fi.org/threads/aptx-adaptive-aptx-lossless-usb-transmitters.961856/page-57

Here's more (direct) updated info about the AptX Adaptive USB transmitter dongles (KB8P, KB9P, YET-T10P): https://www.reddit.com/r/headphones/comments/zr41fe/which_lossy_codec_to_use_compress_with_before/j12cdwt/

Here's more info on TWS adapters like the FiiO UTWS3/5, KZ AZ09 Pro, etc. alongside adapters/converters, AptX Adaptive dongles (KB9P, YET-T10P, etc.), and so on needed for them: https://www.reddit.com/r/HeadphoneAdvice/comments/zvmt4a/wireless_zero_other_wireless_earphones/j1q2s6f/ and https://www.reddit.com/r/HeadphoneAdvice/comments/zz7ukz/is_kz_az09_worth_it/j29ze5u/

For latency, unfortunately it's just inherent Bluetooth tech limitations right now, see here for a bit more info: https://www.reddit.com/r/HeadphoneAdvice/comments/z5pfj4/tws_iem_conversion_thingies/j2ps3qy/

Or ya actually recently some people are using LDAC through Windows 11 or so, check here: https://www.head-fi.org/threads/aptx-adaptive-aptx-lossless-usb-transmitters.961856/page-45#post-17277046

The LDAC for Windows is supposedly from here, it's like in beta mode or something right now: https://www.bluetoothgoodies.com/a2dp/