Will I encounter problems re-entering Thailand by land after multiple visa exemptions?

I have heard that Thailand is cracking down on visa runs where you re-enter by land rather than by air. I wonder if there’s anything in the facts below that are likely to cause problems.

I’m an American citizen. I flew to Thailand from Malaysia on May 27 on a 30 day visa exempt basis and then flew to Bali on June 13 and returned to Bangkok on June 20, again on a 30 day visa exempt basis. Now I’m in Northern Thailand and am contemplating crossing by land over to Vientiane, Laos on June 26, which would still have been within my original visa exemption period.

I would expect to return to Thailand from Laos by land a few days later (again, hopefully, on a visa exempt basis for another 30 days), which would mean 3 entrances into Thailand within about 35 days.

Only the final entrance by land from Laos could reasonably be interpreted as return from a “visa run,” but does anyone think I could encounter a problem when I try to re-enter Thailand from Vientiane?