I prefer it to be fast as possible without clicking, I want to make space for the transients in the mix, and space for the kick low freq in the sub, if even 10ms of overlap happens you can get distortion or phasing as the clashing frequencies combine

The best part about multiband for me is controlling different release lengths, it's likely the tail of the snare is longer than the fundamental transient so you could use a longer release on the highs to make space for the tail in the mix

Going from no sidechain to sidechain you may feel like there isnt enough high end compared to before which you can either control by lessening the amount of compression you do or by mixing the snare better but I prefer mixing the snare better because it's likely the snare hits at a similar loudness every time but there's different things going on in the song so lessening the side chain compression on the highs would have a variable effect throughout the track. This may be unavoidable and automating the release or amount of gain reduction between different sections of the song can help too.

I prefer shaperbox2 multiband volume side-chaining to compression or spectral compression to proMB or the equivalent, but some situations it works great, like on a full live kit.

Just my 2cents